Thomson Reuters names eight Keystone Law partners in its Stand-out Lawyers Guide 2026
Andrea James, Andrew Darwin & Anna McKibbin
“Thank you for the tremendous effort and support. I very much appreciate the work itself but also the manner and professionalism with which it was approached: yet further vindication of our decision to have Keystone supporting us on venture capital deals”
- Joe Seager-Dupuy, Investment Director, True Global
“The support and advice provided by Dee and the Keystone Law team was invaluable, pragmatic and focussed throughout the acquisition and we very much look forward to working together again in the future”
- Michael Denning, Chief Financial Officer, Clinical Partners
Dee is a highly rated corporate lawyer, with over 27 years’ experience in the field. She specialises in venture capital, private equity and a broad range of private company M&A transactions. Dee advises financial institutions and companies on their investments, refinancing’s and shareholder arrangements, as well as corporates (including private equity backed corporates) and individuals on mergers, acquisitions, disposals, and reorganisations and restructurings, in each case across most sectors.
Dee also has extensive experience advising on EIS, SEIS and VCT investments and on transactions in the healthcare, retail and technology sectors.
Dee Sian-Bieleman advises financial institutions, management teams and companies on venture capital and private equity transactions through all stages of the investments, as well as exits, bolt on transactions, corporate governance and reorganisations and restructurings.
Experience
Dee Sian-Bieleman advises corporates, shareholders and investors on domestic and cross-border mergers, acquisitions, disposals, and reorganisations and restructurings, managing all aspects from term sheet, due diligence and deal execution to post-completion integration.
Experience
Dee Sian-Bieleman advises companies in the healthcare sector on their M&A activity, including bolt or strategic acquisitions, as well as advising on reorganisations and restructurings. She also advises financial institutions and investee companies on fundraisings in the healthcare and wellness sector.
Experience
Please note: The experience list above may include examples of work completed prior to joining Keystone Law.
Recognised by The Legal 500 as a Leading Individual for M&A: Smaller Deals, £10M–£100M 2023–2026
Recognised by The Legal 500 for Venture Capital 2018–2026
Recognised as a Next Generation Partner by The Legal 500 for M&A: Smaller Deals, Up To £50M 2014 & 2022
“Dee Sian-Bieleman is always very diligent and thorough. Dee is also very available and has been able to turn work around on an extremely tight deadline including across weekends and holidays”
The Legal 500 2025
“Dee Sian is fabulous – incredibly diligent, proactive and commercial”
The Legal 500 2024
“Dee Sian is very experienced, knowledgeable and understanding. She is meticulous with her work, always having the interests of the client at front of mind”
The Legal 500 2022
“Dee Sian of Keystone Law has a dynamic corporate practice, with strengths in investments, refinancings and restructuring matters. Her recent activity includes acting for Mobeus Equity Partners on its £2.2 million investment into BookingTek”
Chambers UK 2018
“Dee Sian of Keystone Law is 'very good at getting back to you quickly,' notes one client. She is an experienced corporate lawyer who often handles investment and refinancing work”
Chambers UK 2017
“The responsive and pragmatic Dee Sian of Keystone Law is singled out for her experience of venture capital transactions. Clients say: She responds very quickly in all situations, is a good communicator and is firm but pragmatic in negotiations.”
Chambers UK 2016
“Dee Sian is rated for her advice to clients on a range of private equity and venture capital investment transactions, with notable expertise in VCT matters”
Chambers UK 2014
“Knowledgeable and experienced”
The Legal 500
“Extensive experience in the venture capital field and knows her stuff”
Chambers and Partners
Dee qualified as a solicitor in 1998. Prior to joining Keystone Law in 2013, she worked at the following firms: