A five-partner corporate and financial services team has left Willkie Farr & Gallagher in New York to join Bloomberg's in-house legal department.

Partners Dick DeScherer, Dan Grossman, David Levine, Carol Mascera and Sarah Osborne will join Bloomberg on 1 January next year, with DeScherer becoming the media company's chief legal officer.

The Am Law Daily reports that as many as 15 Willkie Farr associates could follow the partners to Bloomberg, but that the specific number is yet to be confirmed. A Bloomberg spokesman said the new hires will join an in-house legal team that already comprises around 35 lawyers.

DeScherer, the chair of Willkie Farr's information systems and technology practice group, already serves on Bloomberg's board of directors, a position he has held for more than 25 years.

Willkie Farr has been Bloomberg's primary legal adviser since 1987, a relationship which will continue in the wake of the team move.

Grossman and Mascara both co-chair Willkie's information systems and technology practice group alongside DeScherer. Grossman specialises in advising tech-driven businesses, while Mascara focuses on IT and e-commerce matters. Meanwhile, Osborne specialises in general corporate and securities work, while Levine advises clients on a range of commercial work including joint ventures, partnerships and strategic alliances.

Bloomberg, which is based in New York, employs more than 15,000 people in 192 locations around the world, and offers a broad variety of media, software, financial and data services. The company's current GC, Karl Kilb, is to stay on in a new role with the Bloomberg Vertical Industries Group, which covers Bloomberg Law, Bloomberg Government and Bloomberg New Energy Finance.

Bloomberg CEO Daniel Doctoroff added: "We are finding unprecedented opportunities for growth in our customer base, our product offerings and our local partners. Bloomberg will benefit greatly from a ramp-up of both the number and range of expertise of in-house legal staff to ensure we are much more efficient and nimble."

The moves come after Willkie Farr advised Bloomberg this August on its biggest acquisition to date – the $990m (£615m) purchase of legal information provider The Bureau of National Affairs.

Willkie Farr co-chairman Steven Gartner said: "This is great news for Bloomberg and Willkie Farr, and it helps solidify a long-term relationship. We've worked with [Bloomberg] for more than 25 years and they've worked with many of these partners for a good chunk of that."