The Australian Competition and Consumer Commission has called for submissions on the "competitive effects" of Commonwealth Bank's proposal to acquire 67 per cent of Aussie Home Loans.The ACCC sent a letter to interested parties on Friday, confirming that it was investigating CBA's proposal, announced in December, to buy all the shares in Aussie it does not currently own. It said it was considering the proposal under section 50 of the Competition and Consumer Act, which prohibits mergers and acquisitions that substantially lessen competition in a market, or are likely to do so.Among the specific questions the ACCC has raised, it wants to know whether market participants consider that the proposed acquisition would provide the merged entity with an ability or incentive to increase prices or profit margins, or decrease the quality of products and services.It wants to know whether the proposed acquisition would result in CBA having the ability and incentive to use its position to originate a larger share of home loans through Aussie's broker platforms.And it wants to know whether the deal would result in CBA having the ability to "foreclose its banking competitors" from accessing its mortgage distribution and other services.The ACCC looked at a similar transaction in 2009, when it reviewed a proposal by National Australia Bank to acquire the mortgage management business of Challenger Financial Services. In the end it concluded that the merger was not likely to result in a substantial lessening of competition.The ACCC has called for submissions by January 31.