Arthur J. Gallagher & Co. is in talks to buy a portfolio of assets from Aon Plc and Willis Towers Watson Plc for about $3 billion, according to people familiar with the matter.

An agreement could be reached in the coming weeks, said the people, who asked to not be identified because the matter isn’t public. Assets in Germany, Spain, France, and the Netherlands as well as Willis Towers’ reinsurance business will be part of the package deal, the people said. No final decision has been made, the structure could still change and discussions could fall through, they said.

The deal is part of the approval process for Aon’s $30 billion agreement last year to combine with Willis Towers, they said. That deal, which will create the largest global insurance brokerage, has been under review by European regulators, which had flagged concerns that the transaction could hurt competition. Aon and Willis Towers recently offered concessions to the European Commission.

Representatives for Arthur J. Gallagher, Aon and Willis Towers declined to comment. Representatives for the European Commission didn’t immediately respond to a request for comment.

Brokerages, which help to connect businesses looking for coverage with insurers, have been merging to diversify, boost commissions and serve customers who want to bypass intermediaries.