Feb 11 (Reuters) - Albemarle, the world's largest producer of lithium, posted a larger-than-expected quarterly loss on Wednesday and said it would idle a major Australian processing plant as it continues to face weak prices for the battery metal.

Shares of the Charlotte, North Carolina-based company fell 3.1% in after-hours trading.

Lithium prices plunged more than 90% over the past two years due in part to oversupply from China, fueling layoffs, corporate buyouts and project delays at Albemarle and peers. While prices have climbed in recent months, they still remain far below all-time highs reached in 2023.

Albemarle said it would idle the last active processing unit, or train, at its Kemerton processing plant in Western Australia after closing another train at the site last year. The company also canceled plans to add two new trains.

"Unfortunately, recent lithium price improvements alone are not enough to offset the challenges facing Western hard-rock lithium conversion operations," CEO Kent Masters said in a statement.

The Kemerton site processed spodumene, a type of hard rock containing lithium, from the Greenbushes mine, the world's largest lithium mine and one Albemarle co-owns with China's Tianqi Lithium.

For the quarter ended December 31, Albemarle posted a net loss of $455.9 million, or $3.87 per share, compared to a net profit of $33.6 million, or 29 cents per share, in the year-ago quarter.

Excluding one-time items, such as charges tied to the upcoming sale of its Ketjen refining catalyst business, Albemarle lost 53 cents per share.

By that measure, analysts expected a loss of 41 cents per share, according to IBES data from LSEG.

While prices remained weak, Albemarle reported a 23% jump in the sales of lithium products.

The company has scheduled a Thursday morning conference call to discuss the quarterly results.