UPDATE 1-MEMC sells Las Vegas solar plant; shares up

June 29 (Reuters) - Silicon wafer maker MEMC Electronic Materials Inc sold a solar power plant in Las Vegas to utility Southern Co and Ted Turner's renewable energy company, sending its shares up as much as 7 percent.

The 20 megawatt Apex Solar project, being built by MEMC unit SunEdison, is expected to start commercial production in the third quarter, SunEdison said on Friday.

Electricity generated at the plant will be bought by Nevada Power Co.

Financial details of the deal were not disclosed.

Power producer Southern Co teamed up with entrepreneur Turner in 2010 to pursue the development of renewable energy projects in the United States. They have already bought a 30 MW project from First Solar Inc.

MEMC shares, which have fallen 47 percent this year due to weak demand for the company's wafers used in the solar and semiconductor industries, rose to a high of $2.24 on Friday on the New York Stock Exchange.