Latham & Watkins and Simpson Thacher & Bartlett have bagged lead adviser roles as private equity group Blackstone Group has agreed a deal to buy real estate company BioMed Realty Trust for $8bn (£5.2bn).

Simpson Thatcher & Bartlett is advising long standing client Blackstone, while Latham & Watkins has been instructed by BioMed Realty Trust.

The transaction is thought to be the largest private equity buyout of a US public company in 2015 so far.

Latham & Watkins' team is led from the firm's San Diego office by corporate partner Craig Garner.

Advice is being provided on tax matters by Los Angeles-based tax partner Pardis Zomorodi and on benefits and compensation matters by fellow Los Angeles tax partner David Taub.

San Diego based finance partner Steve Levine is advising on finance and real estate matters and Orange County-based finance partner Christopher Norton is advising on environmental matters.

The Simpson Thacher team is being led in New York by M&A partner Brian Stadler and real estate partner Krista Miniutti alongside M&A partner Elizabeth Cooper, tax partner Nancy Mehlman, executive compensation and employee benefits partner Greg Grogan and capital markets partner John Lobrano.

Simpson Thatcher has now represented Blackstone in three multi-billion dollar acquisitions of public real estate companies during the past six months.

The firm advised Blackstone in April on its acquisition of Excel Trust, in an all-cash transaction valued at $2bn (£1.3bn).

In February the firm represented Blackstone as it established its eighth global real estate fund, Blackstone Real Estate Partners VIII.