Aussie regulator starts inquiries on Westpac deal

SYDNEY, June 11 (Reuters) - Australia's competition regulator began market inquiries on Wednesday to ascertain if Westpac Banking Corp's (WBC.AX) planned A$15.9 billion ($15 billion) buy of St George Bank Ltd SGB.AX would lessen competition.

The Australian Competition and Consumer Commission (ACCC) said it has instituted two surveys, one for personal banking and other for business banking customers, and asked respondents to submit responses by June 23.

Section 50 of Australia's Trade Practices Act 1974 prohibits acquisitions which substantially reduce competition.

Westpac is offering 1.31 of its shares for every St George Bank share, which would potentially create Australia's biggest bank by market value.

Australia's top four banks, which also comprise of National Australia Bank Ltd (NAB.AX), Commonwealth Bank of Australia Ltd (CBA.AX) and Australia and New Zealand Banking Group Ltd (ANZ.AX), account for about 75 percent of total banking assets and Westpac's proposed deal hinges on regulatory clearance.

Credit Suisse said in a recent report that ACCC's key areas for concern would be small business and retail banking, with particular focus on their businesses in New South Wales and South Australia states.

The report said that Westpac's plans to obtain regulatory clearance by Aug. 29 may prove relatively optimistic considering the lengthy review process that lies ahead. ($1=A$1.06) (Reporting by Denny Thomas; Editing by James Thornhill)