Linklaters and its alliance partners are locked in a series of talks to thrash out a common retirement age following merger.
But chief executive Terence Kyle says the merged practice is most likely to adopt the UK firm's mandatory age of 65 "because it seems to be pretty universal throughout industry, not just in law firms".
Retirement ages differ from country to country. Other firms in the alliance, which consists of six European law firms in Germany, The Netherlands, Italy, Spain, Sweden, Belgium and Luxembourg, generally have a higher retirement age.
Partners at German all-iance firm Oppenhoff & Radler, for instance, retire at 70.
The discrepancies often stem from different qualification ages in individual countries. In Germany, lawyers do not start practising until 29 at the earliest.
Kyle says: "The question of a common retirement age and an agreed solution is something we have discussed. We are looking at how they may be converged.
"The mandatory retirement age at Linklaters is 65, but staff can apply for early retirement at any time after they reach 55."
Kyle says retirement age is of particular concern to younger partnership members who may feel older equity holders are not pulling their weight.
The firm has also failed to decide when full merger is due to go ahead or when the partnerships will vote.
But Kyle says the merger will happen "as soon as it is possible and practicable". He confirms it could be before the end of this year.
Nominated partners from all the alliance members, including Kyle, are holding meetings to consider a range of issues.
As well as the question of retirement, they are looking at common recruitment practices.
Kyle is confident compromises can be reached. "I see no reason why we should not be able to reach an arrangement on retirement ages and with recruitment you will just have to accept the environment you work in," he says.