(Changes story identifier to RIO TINTO - ALUMINA/ from RIO...

(Changes story identifier to RIO TINTO - ALUMINA/ from RIO TINTO - ALUMIA/, dateline, sourcing, adds details and background)

May 21 (Reuters) - Rio Tinto (RIO) has declared force majeure on third-party contracts for alumina exports from its refineries in Queensland, Australia, due to restricted gas capacity levels at its operations, a company spokesperson told Reuters on Monday.

Gas supplies from Rio's Gladstone facilities have been materially affected since an incident on the Queensland gas pipeline in early March, the spokesperson said.

The company said in March that it had been assessing the impact of fires in Queensland on the gas pipeline that supplies the plant.

"Latest information from the pipeline operator is the timing for gas flows to return to full capacity will take significantly longer than expected," spokesperson said.

The pipeline operator's current estimate for a return to normal levels is in the second half of 2024 until when Rio's Yarwun refinery in Gladstone and Queensland Alumina (QAL) will continue to operate at lower capacities.

The mining giant clarified that its aluminium smelters are maintaining their production levels, and the force majeure only affects the third-party contracts.

Bloomberg had earlier reported the declaration by Rio Tinto, citing people familiar with the matter.