Leadership
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Abacus Team and Advisory Council
Helen Hadjichristoudia
Director, CFO
Pavlina Yiannakou
Director, ICS and Head of Regulated Clients
George Koukos
Director, ICS and Head of Trusts
Nassos Paltayian
Director, Head of Compliance
Michaela Malchow
Senior Manager, ICS
Stella Yeropapa
Head of Transfer Pricing
Nicolas Tsiailis
Tax Leader
Nicholas Koronis
Head of Business Process & Service Excellence
Marios Andreou
Director, ICS
Sophia Ioannou
Director, Secretarial Technical Lead
Haris Pavlides
Chief Information Officer
George Kavrigiannis
Tax Leader
Theodoros Verdis
Director, Head of HR
Costas Papageorgiou
Head of Global Workforce & Mobility
Dinos Milios
(Nicosia, CY)

Constantinos Chiotis
CEO
Before repatriating to Cyprus, Constantinos spent about a decade living and working in the US. He started his career in assurance & advisory services with the Phoenix, Arizona office of Deloitte USA. He advised and supported major private and public corporations from various industries in the pacific southwest region, including fortune 500 companies. He later joined PwC where he held senior roles in the firm’s tax & legal services department, advising clients from all over the world on tax matters around M&A and other cross border transactions.
He joined Abacus in 2007 and led an International Business Advisory unit for several years, serving a variety of international clients from US, Canada, Asia, UK and EU. Took over as the firm's CEO as of January 2024. Constantinos has extensive experience in alternative investments, with an emphasis in private equity and venture capital. He has served on a number of boards of European organizations and currently participating in advisory committees and boards of directors of leading European private equity houses.
Constantinos studied at the W. P. Carey School of Business at Arizona State University where he received a BSc degree in Accountancy from the Barret Honors College. He also holds an MBA and is an accredited member of the American Institute of Certified Public Accountants and the Cyprus Institute of Certified Public Accountants. He qualified as a CPA in the State of Arizona during his time with Deloitte in Phoenix.

Helen Hadjichristoudia
Director, CFO
Helen spent her early years in Australia. She started her professional career with PwC and held senior roles with the firm’s international business advisory unit. She joined Abacus in 2001 where she headed one of the firm’s international business advisory units since. In her various roles to date, she has been supporting major private and public corporations from Middle East, Asia and Europe, advising and assisting them with their regional/global expansion and establishing operations in Europe.
Helen has also been advising clients on corporate compliance, financial reporting, corporate governance, and transactional matters. Her main industries of focus have been banking, financial services, commercial drink, and manufacturing/distribution. Helen has participated on a number of boards, committees and advisory units of a number of prominent local and international organisations. Since 2024, Helen has also been acting as Abacus CFO. She graduated with an LLB, Law from University of London. Moreover, she is a Fellow member of the Association of Charter Certified Accountants (FCCA) and is an accredited member of the Cyprus Institute of Certified Public Accountants, for which she served on several advisory committees.

Pavlina Yiannakou
Director, ICS and Head of Regulated Clients
Pavlina started her career with the assurance department of Deloitte where she worked for a total of seven years, having advised a variety of private and public companies from different industries/markets. She joined Abacus’ international business advisory department in 2019, advising and supporting major international groups in technology, venture capital, and private equity.
Pavlina has deep experience and expertise in regulation/licensing, assurance and business advisory. She holds a BSc (Hons) Accounting and Finance degree from London School of Economics and Political Sciences, U.K., (LSE) and is a qualified chartered accountant (ACA) under the Institute of Chartered Accountants in England and Wales (ICAEW).

George Koukos
Director, ICS and Head of Trusts
George started his career with PwC in Cyprus where he held various roles within the firm’s international business advisory practice. He supported clients from various industries and geographies, advising on financial reporting and corporate matters, including banking, compliance etc.
He joined Abacus in 2001 and is now heading one of the firm’s international business advisory units. In his various roles with the firm, George has been advising and supporting major private and public corporations as well as high net worth individuals from Europe, Middle East and the US with their private and corporate (e.g. structuring, financial reporting, corporate governance, compliance, transactional and any other) affairs. Some of the industries in which George has gained substantial experience and expertise are financial services, dredging and offshore energy, agriculture and real estate. George also has extensive experience and expertise on succession and estates planning.
He has deep knowledge on the establishment and administration of trusts and has been advising clients on all aspects of succession planning and inheritance. George has participated on a number of boards (including board of Trustees), committees and advisory units of a number of prominent local and international organisations. He has a BSc in Computerised Accountancy from the University of East Anglia (UK) and an MBA from Leicester University (UK). Moreover, he is a Fellow member of the Association of Charter Certified Accountants (FCCA) and is an accredited member of the Cyprus Institute of Certified Public Accountants. He is also a TEP, full member of the Society of Trusts and Estate Practitioners (STEP), UK and an Associate Member of the International Compliance Association (ICA).

Nassos Paltayian
Director, Head of Compliance
Nassos started his career in assurance, with a focus on financial services companies. He joined Abacus in 2009 and worked in senior roles with the firm’s international business advisory unit.
Since 2015, Nassos has been serving as the firm’s Information Security Officer while simultaneously heading the Abacus Compliance Department. In addition to overseeing all inhouse compliance, risk and information security matters, Nassos and his integrated team of lawyers and other compliance specialists, have been advising a number of local and international private, public and governmental organizations on a variety of compliance, information security, risk and other matters for several years.
In 2014, Nassos became an ACAMS member and soon after a Certified Anti-Money Laundering Specialist. Nassos is also a Certified Risk Management Specialist on Russian sanctions, ISO27001 Lead implementer since 2016 and a Business and Finance Professional (BFP). Nassos has given a number of presentations on both Compliance and Information Security topics in Cyprus and abroad. He served as Chairman of the regulator’s (ICPAC) AML & Compliance committee and founding member and Vice chair of the ACAMS Cyprus chapter. Nassos was also leading the DNFBP module for the National Risk Assessment and participated in numerous task forces for the issuance of Directives, Guidance Notes and Certifications in the field of AML, CTF and Compliance. Nassos is a graduate of the Kingston University in the UK with a Bachelor’s degree (Hon) in Accounting and Finance. Nassos is also a Fellow Chartered Accountant (FCA) with the Institute of Chartered Accountants in England and Wales (ICAEW).

Michaela Malchow
Senior Manager, ICS
Michaela, originally from Germany, commenced her career in operations and customer service roles with Siemens Financial Services in Munich, Germany and Standard & Poor’s Investment Services in Paris, France. She also worked for Financial Times Interactive Data in London, UK. Upon her relocation to Cyprus, she held senior relationship officer roles with boutique local and international financial services firms.
In 2010 she joined Abacus and today leads one of the firm’s international business advisory units from the group senior manager role. In her various roles with the firm, Michaela has been advising and supporting major private and public corporations as well as high net worth individuals from Europe, Middle East and the US with their private and corporate (e.g. financial reporting, corporate governance, compliance, transactional, other) affairs. Some of the industries in which Michaela has gained substantial experience and expertise are real estate, consumer electronics and shipping. Michaela also has extensive experience and expertise on trusts, estates and succession planning and advises clients on inheritance, asset protection and wealth accumulation matters. Michaela has participated on a number of boards and committees of prominent local and international organisations. Michaela commenced her studies in the south of France, followed by a BS in Finance, Entrepreneurship & International Studies from Kelley School of Business, Indiana University Bloomington in the US. She speaks German, English, French and Greek.

Stella Yeropapa
Head of Transfer Pricing
Stella has almost 20 years of experience in international tax and transfer pricing. Prior to joining Abacus in 2021, Stella spent 16+ years with PwC. As a Senior Tax Manager she had overall responsibility in managing the tax affairs of a portfolio of local and international corporate groups, active in various industries and markets. Her main responsibilities included international tax planning, advising on deal structuring, reorganisations, tax ruling applications, tax office examinations, as well as M&A transactions.
As the Abacus Head of Transfer Pricing, Stella's experience has primarily been focused on large corporates with extensive operations across the world, where significant changes are being made to the operating and transfer pricing models. Stella has worked extensively with clients to develop and implement new business operating models and design and implement transfer pricing policies that align to these models. Further, Stella has helped clients with preparation of TP documentation, TP audits, putting in place robust global transfer pricing documents, and ensuring certainty for her clients when it comes to their intercompany arrangements. Stella also has a focus on operational transfer pricing, ensuring her clients have the appropriate controls and processes in place from a transfer pricing perspective and determining and implementing solutions to allow for transfer pricing to be implemented with greater automation.
Stella studied Business Administration with the University of Cyprus and is a fellow member of the Association of Chartered and Certified Accountants (FCCA).

Nicolas Tsiailis
Tax Leader
Nicolas is a Tax Leader in our firm's Tax Practice and specialises in the taxation of corporates, asset managers, institutional investors as well as individual shareholders and top executives. He has extensive experience advising on the tax aspects of all types of transactional matters, such as private equity, venture capital, public and private M&A, reorganisations, returns of capital, dividend distributions, carried interest etc. He has broad experience which encompasses working for private groups as well as international alternative asset management houses on all the issues that affect their businesses, including in relation to corporate/fund structuring and ongoing tax compliance. Most of Nicolas work has a cross-border element, with deep local insight and expertise combined with global intelligence.
Before joining Abacus in 2019, Nicolas worked as a Senior Manager at PwC, specialising in Tax Advisory and Tax Compliance Services. He is currently a Tax Leader in the Tax practice of Abacus and deals with all aspects of local compliance and international tax planning. Nicolas is a holder of a BA (Honours) degree in Accounting and Finance from De Montfort University UK and is a Fellow Chartered Certified Accountant (FCCA) under the Association of Chartered Certified Accountants and is an accredited member of the Cyprus Institute of Certified Public Accountants.

Nicholas Koronis
Head of Business Process & Service Excellence
Before repatriating to Cyprus and joining Abacus, Nicholas lived and studied in the UK for about a decade. He started his career with a boutique business and tax advisory firm in London, where he worked for a total of seven years, advising private and public UK companies of all sizes and industries with their tax and corporate affairs. He has been with Abacus for the past 15 years as a senior member of our firm’s international business advisory service line. Nicholas is currently heading one of our firm’s international business advisory units, advising and supporting major international groups in infrastructure, transportation, private equity, and technology. Nicholas has deep experience and expertise in regulation/licensing, assurance and business advisory. Nicholas has a BA in Accounting and Finance from Kent University in the UK and is a qualified chartered accountant under the Institute of Chartered Accountants in England and Wales (ICAEW) and an accredited member of the Cyprus Institute of Certified Public Accountants.
He is also a holder of the Cyprus Securities and Exchange Commission (CySEC) Advanced Certificate in Financial Services legal framework.

Marios Andreou
Director, ICS
Marios has been working with Abacus in different roles within business advisory and corporate services for around 20 years, and currently heads one of the firm’s international business advisory units. He has been advising and supporting major multinationals and other companies from US, Canada and Middle East from a variety of industries.
His main sectors of focus have been private equity, technology (with an emphasis in FinTech) and infrastructure/construction. Marios has served on a number of boards and committees of prominent global organisations. He has a BSc in Accounting from University of Carbondale (USA). Marios qualified as a Certified Public Accountant (CPA) during his time in the US and an accredited member of the American Institute of Certified Public Accountants as well as the Cyprus Institute of Certified Public Accountants.

Sophia Ioannou
Director, Secretarial Technical Lead
Sophia has 35+ years’ experience in corporate secretarial, legal and corporate governance matters. She started her career with PwC where she held a number of senior roles with PwC’s corporate secretarial specialist department. She joined Abacus in 2001, and has been heading the firm’s corporate secretarial division for many years, delivering clients from all over the world with expertise in fulfilling all corporate secretarial functions. Sophia has served on a number of boards and committees and also acted as company secretary for numerous prominent organizations.
She has advised and supported the chair and boards of companies on their responsibilities under the rules and regulations, ensuring boards functioned efficiently and effectively, with quality information flows within the boards, respective committees, senior management, and non-executive directors. She has also developed and oversaw systems that ensure companies complied with all applicable bylaws, regulations, legal and statutory requirements. Sophia is a certified International Finance & Administration practitioner.

Haris Pavlides
Chief Information Officer
Haris has 25+ years of experience in IT Consulting and Business Technology transformation services. He started his career with legacy Coopers&Lybrand -Management Consulting Services, which subsequently became PwC-Consulting and later IBM Global Business Services based in numerous countries over the years including Denmark, Switzerland, Germany, UK prior to returning to Cyprus and joining Abacus as CIO.
During his professional career he gained in-depth knowledge on leading-edge technologies and breadth of experience in Digital Transformation, Program & Portfolio Management, IT Consulting and Systems implementation within major IT projects, leading IT solutions teams through strategic initiatives that mapped business objectives to technology applications improving organizational performance. Haris’ contribution covers throughout the spectrum of Information and Communication Technology consultancy and Program Management services, from Strategy to Systems Development and ERP Implementation in the Financial, Aviation, Communication, Energy, Utility, Public, Healthcare and Insurance sectors / industries in a multinational client environment including Fortune Global 500 corporations.
In addition to leading the firm’s inhouse information technology and security affairs, Haris’ and his team of experts also advise and support our clients with their own technology and information security challenges. Haris holds a Master’s Degree in Information and Communication Technology by the University of Wollongong (Australia), an MBA by Edinburgh Business School (UK) and a Professional Certificate for Technology Entrepreneurship by Harvard University. Haris is qualified as a Project Management Practitioner by AXELOS UK, a member of the Executive Committee of the IEEE Cyprus Section and a qualified member of the Scientific Technical Chamber of Cyprus (ETEK) and the Cyprus Computer Society.

George Kavrigiannis
Tax Leader
George is an international tax specialist with 15+ years of experience advising and supporting multinationals, private equity houses, venture capital groups, family offices and other clients with issues that impact their business. George started his career with a Big 4 firm, worked in multiple EU countries and has been with Abacus for the past 9 years, acting as Tax Lead and advisor to a number of clients from Europe, US and Canada.
George holds a BSc in Economics and Business Economics from Aristotle University in Thessaloniki and an MSc in Accounting and Finance from the University of Edinburgh (UK). George is also a proud member of the Army Reserve and has been trained on various missions as part of the EU Battlegroup response force.

Theodoros Verdis
Director, Head of HR
Theodoros started his career with PwC Advisory, where he consulted local and international (EU and Middle East) clients on business and HR matters, including performance management, executive recruitment, organizational restructurings, training & development, design and implementation of training programs and development centers and change management initiatives. He joined Abacus in 2012, heading the firm’s HR division, which covers both internal HR management as well as client advisory and support projects. He has been advising numerous international clients mainly in venture capital and technology, with a variety of projects.
Theodoros studied Business Administration (BSc) at La Verne University (USA) and obtained his Master’s degree (MSc) in Human Resource Management from the University of Manchester (UK).
Theodoros also qualified with the Society of Human Resource Management as a SHRM Senior Certified Professional.

Costas Papageorgiou
Head of Global Workforce & Mobility
Constantinos brings over a decade of expertise in assurance, accounting, tax, and payroll. Constantinos began his professional journey with Deloitte’s assurance department, where he spent over five years contributing to diverse local and international audit projects. His work included high profile multinationals groups, including a financial and commercial banking services conglomerate. Constantinos joined Abacus in 2019 as an international business and tax advisor, specialising in the strategic tax planning and local tax compliance for individuals. Constantinos also possesses extensive experience in managing payroll, ensuring compliance with applicable labour laws, and maintaining accurate employee compensation records.
Constantinos holds a Bachelor’s Degree in Business Administration, majoring in Accounting and Finance, from the University of Cyprus. He is a member of the Institute of Chartered Accountants in England and Wales (ICAEW) and a member of the Institute of Certified Public Accountants of Cyprus (ICPAC) since 2018.

Dinos Milios
(Nicosia, CY)
Dinos Milios (Nicosia, Cyprus)
Dinos Milios is a Partner at Shipping Finance Solutions, a regional advisory firm specializing in all aspects of financing for the shipping sector. He is an accomplished finance professional with 24 years of experience in investment banking, corporate finance and banking. His previous roles included Financial Advisory Services (KPMG), Project Finance (Societe Generale group), Investment Banking / Corporate Finance (Marfin/Laiki group), and Corporate Credit / Shipping Finance (Eurobank).
He started his career as M&A advisor to private and public entities within a broad range of industry sectors. He then moved on to project finance and investment banking, and was responsible for mergers, acquisitions and management buyouts, public infrastructure projects, private energy and construction projects, as well as capital market transactions involving debt, equity and hybrid instruments. He then pursued a 15-year career in the banking sector, originally in large corporate credit, and afterwards heading Eurobank’s shipping finance department, overseeing its successful development and growth from inception to a nationwide leader. In his current role at SFS, he is mainly involved in advising shipowners, funds and family offices on capital structure matters, and sourcing debt capital from a range of financiers internationally (banks, leasing houses, credit funds) as well as from equity investors. He is also advising financial institutions on setting up and running ship lending operations, and also deals with other specialized projects within the shipping space and beyond.
Throughout his career, Dinos has been responsible for debt and equity transactions exceeding Euro 2 billion in aggregate. His past industry expertise, in addition to shipping, includes energy, hotels and leisure, food & beverage, wholesale trade, telecoms, real estate and education.
Dinos holds a Bachelor’s Degree in Mathematics and Philosophy from King’s College London, and a MSc in Shipping, Trade and Finance from Bayes Business School.