Loss adjuster Capita McLarens is understood to have put a proposal to insurer ACE that would put all ACE's pre-1999 London Market run-off business into one portfolio.
A spokeswoman for ACE in London refused to comment on the likelihood, while a spokeswoman for Capita McLarens said: "We have no comment. We never comment on speculation."
The London Market operations of Bermuda-based ACE have experienced several changes in recent times.
A source close to the company said: "Their Lloyd's and global market operations seems to have gone through one change after another."
"Formal news may emerge soon," he said.