Westpac has announced that it plans to loosen requirements for mortgage brokers to claim certain upfront commissions.In a move seemingly aimed at recapturing support from mortgage brokers across the country, Westpac said from January next year it will not require brokers to invoice the bank for originating additional credit from home borrowers.Under existing arrangements brokers have to wait up to four weeks before Westpac pays them so-called "subsequent upfront commissions" for arranging add-on lending to fund renovations.For example, if a borrower draws down funds from an offset account in the twelve months following settlement, the broker will received a subsequent upfront commission calculated on the additional borrowed amount.From January next year Westpac will award such commissions automatically to brokers.Home loan growth at Westpac and other major banks has been eroded in the last 18 months by a raft of non-bank lenders marketing sharply priced mortgages.The size of Westpac's mortgage book has declined by almost A$7 billion since the end of June, according to APRA's monthly banking data.Given their recent market share losses, major banks could come under pressure to review the broker incentives as part of their strategies to recapture momentum in their lending operations.