CMS is a reference in the market for energy, ESG and real estate projects, including structuring and financing, environmental queries, and assistance with the construction and purchase of facilities. The group has a track record in public private partnerships, particularly in the context of airports, railways and gas pipeline infrastructure. The team is led by three practitioners: Kostadin Sirleshtov is active in energy and infrastructure projects; Dimitar Zwiatkow is a key contact for regulatory, corporate and financing matters; and Borislava Piperkova has in-depth knowledge of renewable and nuclear energy projects. Piperkova was promoted to the partnership in April 2025.
Legal 500 Editorial commentary
Accolades
Client satisfaction: Lawyer & team quality
Testimonials
Collated independently by Legal 500 research team.
- 'The projects and PPP team distinguishes itself through its strong coordination and ability to manage complex, multi-party processes effectively. They are responsive, pragmatic, and able to provide guidance that keeps transactions moving forward in a structured way. Potential clients would value their experience across different project stages, as well as their clarity in communication, which makes it easier to navigate challenging issues. The team also works in a collaborative manner with counterparties, which often helps to avoid unnecessary delays and supports smoother execution.'
- 'Excellent client relationship management, responsiveness and accessibility. Strong depth of team and international network.'
- 'Dimitar Zwiatkow and Konstantin Altandzhiyski have an excellent understanding of our business and commercial awareness. Excellent legal knowledge and ability in combination with innovative solutions.'
- 'The individuals I have worked with stand out for their responsiveness, clear communication, and ability to manage issues under time pressure. They are approachable, dependable, and take a pragmatic view, which makes their advice easy to apply in practice. I have particularly valued their consistency and availability, even when matters have been urgent or complex. Dimitar Zwiatkow has been especially effective in coordinating the work and ensuring that progress is maintained without unnecessary delays.'
- 'Excellent collaboration. Good technical response supported by innovative problem solving.'
- 'The Bulgaria team in CMS demonstrated excellent professional expertise and are good with keeping deadlines and anticipating client needs.'
Key clients
- Skoda Group
- DSK Bank
- Aratiden
- Taaleri Energia Finland
- Copenhagen Infrastructure Partners (CIP)
- Actis / Rezolv
- Shell
- OMV Petrom
- Toshiba
Work highlights
Representing Skoda Group in winning two tenders for electric trains by Bulgaria's Ministry of Transportation worth €700m.
Advised Toshiba International on a repair and rehabilitation agreement with the Bulgarian state-owned National Electricity Company for the pumping storage hydro power plant Chaira Unit 1.
Advising the lender, DSK Bank, on the €58.5m financing to for the development of a PV plant, with a total capacity of 40 MW and BESS (93 MW/h).
Lawyers
Leading partners
The strongest partners in their field, leading on market-leading deals and endorsed by peers and clients alike.
Next Generation Partners
Junior partners with significant recognition from clients and peers in the market and key roles on multiple matters.
Practice head
Kostadin Sirleshtov; Dimitar Zwiatkow; Borislava Piperkova
Other key lawyers
Konstantin Altandzhiyski; Denitsa Dudevska