General Electric Co and Britain's Rolls Royce Group PLC said on Wednesday they have halted tests on an alternate engine for the F-35 fighter jet after damage was found to some turbine blades, and no timetable was given for the tests to resume.

Tests in Cincinnati last weekend revealed dings and nicks on the turbine blades but no damage to the compressor or the fan. The engine was running normally at the time of the shutdown, GE and Rolls said in a joint statement.

It's why you run jet engines to their limits during the development program -- to identify potential issues, the statement said.

More details are expected in a few days.

Lockheed Martin Corp builds the F-35. Pratt & Whitney, a unit of United Technologies Corp , builds the plane's main engine.

Congressional negotiators agreed on Tuesday to include $560 million in the current fiscal year to pay for the alternate engine. The Obama administration opposes funding for it.

(Reporting by Andrea Shalal-Esa; Editing by Gary Hill)