Oppenhoff & Rädler's plans to merge with Linklaters & Alliance are being held up by a legal technicality, though the contract is expected to be completed for voting as early as next month.
At present a "yes" verdict is predicted when the final documents are released to partners at the German firm this summer, including details of the global lockstep system.
The problem has arisen from the fact that tax advisers within the German firm cannot officially be recognised as "partners" under English law.
The two firms are currently said to be in talks to see how this issue can be resolved, though according to a source the merger is still expected to go ahead as planned.
He says: "We are at the final stage of negotiations now and although there are no cultural or political difficulties on either side, we have a lot of partners who are tax advisers with a business rather than legal education. It is just a case of seeing how we can find a solution to this problem.
"In terms of the relationship between ourselves and the other firm members, there is no question about its success and no doubts about the merger.
"It has been just as we had expected and together we are already dealing with more than 1000 joint matters. Linklaters is already bringing us success and it is bringing us profits.
"To other firms in Europe it might not seem like it is necessary to belong to a leading law firm today, but tomorrow it will be."
If the vote is positive, Oppenhoffs will merge ahead of fellow alliance members De Brauw Blackstone Westbroek (Netherlands), De Bandt van Hecke Lagae & Loesch (Belgium and Luxembourg), Lagerlöf & Leman (Sweden) and Gianni Origoni & Partners (Italy), which are officially due to join up with Linklaters in the UK on 1 January 2002.
Earlier this year, the two firms were locked in talks to resolve an issue over differing retirement ages (The Lawyer, 28 February).
Linklaters chief executive Terence Kyle was unavailable for comment.