Private equity fund The Blackstone Group has appointed a new top lawyer with the hire of John Finley, the co-chair of Simpson Thacher & Bartlett's M&A group, reports The Am Law Daily.

Notable transactions that Finley has worked on in recent years at Simpson Thacher include representing Lehman Brothers on the sale of its North American operations to Barclays and Mars's $23.1bn (£15.3bn) leveraged buyout-style purchase of chewing gum manufacturer Wrigley.

Finley's work on the Mars deal earned him a spot in The American Lawyer's list of Dealmakers of the Year in 2009.

Blackstone is a longtime Simpson Thacher client and the US firm has advised the private equity giant on a raft of transactions including its landmark initial public offering in 2007.

"This is a terrific opportunity for John to join a highly valued and longstanding client of our firm," Simpson said in a statement. "We wish him well and look forward to continuing to work closely with him and his colleagues at Blackstone."

The move comes after three partners from Cravath Swaine & Moore partners left to take up senior in-house role over the last four months, including Francis Barron, who joined Morgan Stanley as its new chief legal officer.

The Am Law Daily is a blog on law.com, Legal Week's US sister title.