ZURICH, Dec 6 (Reuters) - Clariant cut its full year earnings guidance on Wednesday after it said it would close its bioethanol plant in Romania and downsize its operations in Germany.

The Swiss company said 120 jobs would go with the closure of the Podari facility in southern Romania, while another 50 would be cut at its biofuels and derivatives operations at Straubing, Planegg and Munich in Germany.

Podari was designed to convert 250,000 tons of straw into cellulosic ethanol, a product used to make laundry detergents, cleaning agents and products used in industry and personal and home care.

But the facility, opened by Clariant in 2021, ran up losses after technical problems such as bottlenecks meant its production never reached full capacity, Clariant CEO Konrad Keijzer told reporters.

"We had a 50,000 ton capacity plant and couldn't get it to run anywhere close to capacity," he said. "The economics were not there.

"The demand for second generation biofuel is there, the commercial side of this business case is very attractive and remains very attractive," he added. "There is a strong demand, but we had technical problems."

Podari had run up losses of 77 million Swiss francs ($88.06 million) since the third quarter of 2022, Chief Financial Officer Bill Collins said.

Clariant said it expected a negative impact on its 2023 operating profit of 170 to 200 million francs from the decision, including in a 60-90 million reduction in earnings before interest, tax, depreciation and amortisation (EBITDA).

As a result, the company reduced its guidance for 2023 EBITDA to 570 to 600 million from 650 to 700 million previously.

($1 = 0.8744 Swiss francs) (Reporting by John Revill Editing by Kirsti Knolle and Mark Potter)