Freshfields has entered into talks with German firm Deringer Tessin Herrman & Sedemund as part of a review of its German operation.
The firm, which to date has developed through organic growth in Frankfurt, is reconsidering its strategy, according to chief executive Alan Peck.
He said that Freshfields was "thinking about the future" in Germany and had met with many German firms, of which Deringer Tessin was one.
According to Dr Joachim Pfeffer, a partner at Deringer Tessin, his firm is engaged in talks with Freshfields but is also talking to other London-based firms. He stressed that the talks were at "a very initial stage". It was "premature to deal with the question of merger", he said, but added that "in this changing world you cannot say there will never be a merger".
He said Freshfields was an attractive proposition because of its success in "going global".
News of Freshfields' review follows the poaching by Clifford Chance in August of 11 lawyers, including three partners, from the Frankfurt office of Wessing Berenberg-Gossler Zimmerman Lange.
One observer said: "They have obviously looked at how Clifford Chance has taken the Frankfurt branch of a major German firm and how it is working for them."
However, he added, the biggest obstacle was coping with the different schemes of partnership.
"The good partners at Deringer earn a lot of money. They would have to come in at a senior level."
Deringer Tessin is a second tier German firm, particularly known in the mergers and EU field. It also has a highly-regarded business practice.