(Reuters) - Australia's Western Mine Workers Alliance (WMWA) said on Thursday that more than 400 workers at Rio Tinto's Paraburdoo iron ore mine in Pilbara region have signed a petition to support collective bargaining.

The petition was launched by the alliance to initiate bargaining for a collective agreement at the mine for the first time in over 20 years.

Paraburdoo mine is part of Rio's Western Australian operations, which employs around 16,000 employees and shipped 328.6 million tonnes in 2024, the company website showed.

The Australian Workers' Union and the Mining and Energy Union (MEU) together form the WMWA.

The agreement would likely bring about annual pay increase, a relief in the current high-living-costs environment among other demands, MEU had said last month.

The alliance said in a Facebook post it expects to make a formal application to the Australia's industrial tribunal, the Fair Work Commission, to release an order for Rio to collectively bargain with its mine workforce.

A Rio Tinto spokesperson said in an emailed response that its current approach helps drive productivity and wages growth.

"This model has delivered for our people, our business and the Australian economy, through the creation of jobs, strong and sustained wage growth, and the payment of royalties."

(Reporting by Sneha Kumar in Bengaluru; Editing by Mrigank Dhaniwala)