SYDNEY - Australia's historic move toward legalizing same-sex marriage could bring businesses a massive windfall of "pink dollars" as tens of thousands of gay couples tie the knot, economists said Wednesday.

Legalizing same-sex marriage is expected to pass parliament by the end of the year after the announcement Wednesday that Australian voters had resoundingly backed it in a national poll.

With nearly 50,000 same-sex couples in Australia, and countless gay tourists who could come to the country to marry, the wedding industry is in for a boom.

"We've got this pent-up demand and we could see over the next year or so, once the legislation is passed, a sharp increase in the number of weddings," ANZ senior economist Felicity Emmett told AFP.

The ANZ estimated the boon to business generated by gay weddings in the first year after legalisation could surpass Aus$650 million (US$490 million).

Other immediate financial benefits could include an increase in overseas visitors who choose to marry and honeymoon in the nation, and Australian expats returning to get hitched.

"From a tourism point of view, the pink dollar is big business and same-sex marriage tourism is on the rise," Tourism Australia managing director John O'Sullivan said.

"Nearly half of LGBTI couples who tied the knot in New Zealand last year came from other countries. Legalizing same-sex marriage would undoubtedly bring similar... tourism benefits."

There are also long-term benefits from giving same-sex couples certainty in their relationship status, University of Sydney senior economics lecturer Hayley Fisher said.

"They can make better commitments to each other and decisions about investing in their relationships that may also have flow-on effects to the economy," Fisher told AFP.

"We can expect to see things like more home ownership for same-sex couples."

More than 30 major business leaders voiced support for marriage reform earlier this year, telling Prime Minister Malcolm Turnbull in a letter that it was "very clear... the business case for supporting civil marriage equality is compelling".

"Enabling loving, committed couples to be married, regardless of their sexual orientation will contribute to a stronger economy and a more inclusive Australia."

Benefits of the "pink dollar" have already led more businesses to lend their names to high-profile events such as the iconic Gay and Lesbian Mardi Gras, which generates millions for Sydney's economy each year.

© Agence France-Presse