Nabarro Nathanson has withdrawn from Warsaw and transferred its practice to Allen & Overy in a move that will make Allen & Overy a top three foreign firm in Poland.
Under what Nabarros is describing as an "amicable arrangement", partners Michael Davies and Tomasz Dobrowolski and their associates are transferring to Allen & Overy.
Nabarros said its main motivation for the arrangement was to find a "good home for its lawyers" and it had nothing to gain from the move.
The firm, which had planned to expand its Warsaw office from 15 to 20 lawyers a year ago, suffered a setback when it lost five lawyers, including two partners, to McKenna & Co's Polish office last October.
A Nabarros source denied there was any link between the decision to close the Warsaw office and the loss of the five.
Stephen Shone, one of the McKennas defectors, said he was very pleased that Davies and Dobrowolski, the two remaining partners, had found a firm to go to.
Shone said he left because he did not feel Nabarros was properly committed to the region. He now believes this may be behind Nabarros' latest move. Shone claimed that five years on from setting up in Warsaw, firms were now reassessing their positions.
"Some firms have been successful, some have failed," he said. "The team I took with me six months ago has billed more than the Nabarros office had done in the previous year. Nabarros could have been very successful with the right commitment and attitude."
David Bramson, Nabarros' senior partner, said: "We took a strategic decision to transfer the Polish office to another firm last year. While the Polish office has met its targets, it no longer fits with the direction of our business."
Stephen Denyer, head of Allen & Overy in Warsaw, was "delighted" at the recruitment, which he said "consolidates our position in the premier league in Poland".