Gallagher International is in talks to buy fellow London market broker Oxygen, insurancetimes.co.uk understands.

If successful, it will be the second big acquisition of the year for the UK-based arm of US broking firm Arthur J Gallagher. Gallagher International bought broking group Heath Lambert in May for £97m.

Gallagher International was also on the M&A trail in 2010, completing a takeover of Lloyd’s broker First City in March.

It will also not be the first deal Gallagher has done with Oxygen. It bought the broker’s MGA arm, Oxygen Insurance Managers, in September 2008.

As revealed by insurancetimes.co.uk last month, Oxygen reported an 86.5% profit drop in 2010 to £95,229 from £707,398 in 2009.

The broker attributed the sharp decline to the turbulence caused by the untimely death of Sean Hicks, the head of Oxygen’s Leeds-based corporate risks department, in 2009, and the subsequent defection of some of his former colleagues in 2010.

Oxygen and Gallagher were unavailable for comment.