Adds details and background in para 2-6, analyst comments in para 8

By Shivangi Lahiri and Shruti Agarwal

Feb 20 (Reuters) - Australia’s Mineral Resources MIN.AX reported stronger‑than‑expected interim earnings on Friday, buoyed by steady nameplate‑capacity output from its flagship Onslow Iron project and a rebound in lithium prices.

Volumes from the group's mining services rose 22.1% to a record 166 million wet metric tons as its Onslow project hit nameplate capacity in August and operations recovered after haul‑road upgrades carried out following a road‑train accident earlier in the year.

Onslow Iron production rose to 17.3 million wet metric tons on a 100% basis compared to 6.3 million wet metric tons a year earlier.

The mining services division posted underlying EBITDA of A$488 million for the first half, up 29% on the year, helping lift group EBITDA to a record A$1.2 billion, a staggering 286% rise from last year.

"Onslow Iron is now a proven, cash‑generative operation,” board chair Malcolm Bundey said, adding that the mining services business “continues to deliver superior performance.”

Meanwhile, MinRes’ lithium division delivered underlying EBITDA of A$167 million, a more than tenfold increase from last year as prices of the battery metal surged amid rising battery storage demand and the supply squeeze after the August production halt at CATL's Jianxiawo mine.

This resulted in a swing to underlying net profit after tax of A$343 million ($242.16 million) for the half year, reversing an A$196 million loss a year earlier and topping the Visible Alpha consensus estimate of A$288.9 million.

"The financial and operating improvement at MIN has been remarkable. The company is not yet in the promised land of distributing excess cash to shareholders, but it has a map and some momentum to get there," Sandstone Insights analysts said.

MinRes opted against declaring an interim dividend, focusing instead on deleveraging amid considerable scrutiny over its capital spending at Onslow.

Net debt eased by A$471 million, after capital outlays had pushed it to A$5.3 billion at end‑FY2025, a level that had raised concerns among investors.

Shares of the lithium miner rose as much as 4.3%, hitting an over two-week high, but closed over 5% lower.

($1 = 1.4164 Australian dollars)

(Reporting by Shivangi Lahiri and Shruti Agarwal in Bengaluru; Editing by Rashmi Aich)

((Shivangi.Lahiri@thomsonreuters.com;))