The management and executive committees of Dewey Ballantine and Orrick Herrington & Sutcliffe have recommended the firms' merger to their respective partnerships.
As first revealed on www.thelawyer.com (25 October), the new firm will be named Dewey Orrick but will retain Orrick's 'O' brand. It is hoped that the partners will vote on the merger in mid-December and complete it by 1 January 2007.
Dewey London managing partner Fred Gander told The Lawyer: "We've cleared the major issues such as firm name and senior management and now we're getting down to the nitty-gritty."
Dewey chairman Morton Pierce and Orrick chairman Ralph Baxter will be co-chairs of the combined firm, with Baxter serving as presiding partner. Baxter will be more involved with day-to-day management, whereas Pierce will continue his M&A practice.
The firms have general agreement on the composition of the executive committee, which will decide on ongoing management issues, and the policy committee, which will make overall strategy decisions.
Pierce said: "The firms have set a demanding timetable but are ahead of schedule, with practice group heads and office managing partners pretty much sorted.
"I think it's doable. We've been talking for a while and we have a good understanding."
Gander said: "We're entering the phase of due diligence and getting all the partners to meet each other."
Pierce added: "Documenting deals is easy, but physically putting two entities together is not what lawyers normally do. There are a lot of details to sort out."
One of the details that has been resolved is the all-important New York real estate issue. Orrick's 160 lawyers in the Big Apple will move into spare space at Dewey's headquarters at midtown Manhattan's Corporate Row, just blocks from the Rockefeller Center and Central Park.
The arrival of the Orrick team will boost the New York office to around 500 lawyers.
If the merger comes to fruition the combined firm would house nearly 1,500 lawyers and come close to £530m in revenue. Its London presence would top £33m in turnover.
As revealed by The Lawyer UK 100 Annual Report 2006, Dewey has the larger London office of the two firms in terms of turnover, generating £20.3m in 2005-06.
San Francisco-based Orrick reported around £13m in London, but that figure will be boosted this year by the addition of Coudert Brothers' London office, which joined last year.
Orrick takes the lead on headcount with 60 lawyers, compared with Dewey's 45 lawyers and nine fee-earners.
The combined firm would have one of the largest US presences in Europe, with 300 lawyers spread across seven offices.