Canberra, May 29 (IANS): Some of Australia's biggest businesses on Friday posted newspaper advertisements supporting gay marriage.

Corporations, including Google, Qantas Airline - Australia's flagship carrier, Optus - the country's second largest telecommunications company and the ANZ and Commonwealth banks, have put their names to a list of Australian businesses backing marriage equality, ABC reported.

Others supporters include law firms Slater and Gordon and Gilbert and Tobin, and the Football Federation of Australia.

Australian Marriage Equality national director Rodney Croome said the corporations approached the organisation to send the message that the country's business community supported marriage equality.

He said corporations understood the importance of respect for diversity in the workplace and equality for staff and customers.

The same-sex marriage debate in Australia gained momentum this week on the back of Ireland's hugely successful referendum last week.

Prime Minister Tony Abbott has emphasised any moves to legalise gay marriage must be owned by the Parliament, and not just by a single party.

Abbott's sister Christine Forster, who is engaged to a woman said she believed gay marriage would be legal in Australia by the end of the year.