July 31 (Reuters) - Lynas Rare Earths on Monday posted a 47% drop in fourth-quarter revenue on lower prices for rare earths products, and said it was targeting its first production of mixed rare-earths carbonate from its Kalgoorlie facility in September.

Lynas, the world's largest producer of rare earths outside of China, said its sales revenue was A$157.5 million ($104.85 million) for the three-month period ended June 30, compared with A$294.5 million a year ago, and a consensus estimate of A$216 million, according to Barrenjoey.

Prices of rare earth minerals have declined over the last year because of increased supply from top producer China and soft demand from green energy companies and automotive sector.

"Future pricing trends will depend on the economic recovery in China and the Chinese production quota for the second half of 2023," Lynas said in a statement.

The average selling price for the miner's product range came in at A$38.90 per kilogram (kg), compared with A$79.20 per kg last year.

Production of Neodymium-Praseodymium Oxide (NdPr) reached a record 1,864 metric tons in the quarter, compared with 1,579 metric tons a year earlier.

Lynas added that full plant commissioning commenced for the Kalgoorlie rare earths processing facility in Western Australia during the quarter, targeting first production of mixed rare-earths carbonate in September 2023, a month later than previously expected.

The company has been racing to complete construction of the Kalgoorlie facility amid concerns its Malaysian facility would have to be partly wound down after domestic regulators raised concerns about radiation levels from the process of cracking and leaching.

In May, the company's operating licence in Malaysia to import and process rare earths was extended until Jan. 1, 2024, but it is continuing to seek legal review of conditions that threaten its permit.

Shares of the Lynas rose as much as 4.9% by 0046 GMT, while the broader market was 0.4% higher.

($1 = 1.5022 Australian dollars) (Reporting by Ayushman Ojha and John Biju in Bengaluru; Editing by Kim Coghill, Sherry Jacob-Phillips and Jamie Freed)