Global broking group, Arthur J Gallagher is to buy insurance premium funding businesses Monument and Lumley Finance from Wesfarmers.Gallagher is also buying Wesfarmers' insurance broking business.Chicago-based Gallagher has been building its business in Australia since the 1990s. It operates in Australia primarily as a commercial property and casualty broker.Wesfarmers said Gallagher would pay A$1.01 billion for its businesses. In addition to the purchase price, Wesfarmers will receive a distribution of approximately $150 million to repay funding of the premium funding operations.These sales complete Wesfarmers exit from the insurance sector, with some of the proceeds no doubt intended to capitalise its new banking business being established through Coles.