July 16 (Reuters) - Shares of First Solar Inc rose 8 percent after the company installed an additional 100 megawatts in less than 12 weeks at an Arizona solar power plant.
The plant, which is expected to be completed in 2014, reached a 100 MW milestone in April.
First Solar declined to say if the plant would be completed earlier than planned.
MidAmerican, the utility affiliate of Warren Buffett's holding company, Berkshire Hathaway Inc, and NRG Energy Inc hold stakes in the 290-MW Agua Caliente project in Yuma County, Arizona.
The plant is supported by a $967 million loan guarantee from the U.S. Department of Energy.
First Solar shares were up 7 percent at $15.26 on Monday on the Nasdaq. They touched a ten-day high earlier in the session.