UPDATE 2-SunPower to build solar plants for FPL, stock up

(Adds background, previous NEW YORK)

LOS ANGELES, July 10 (Reuters) - SunPower Corp SPWR.O will build the largest U.S. photovoltaic solar power plant in Florida for FPL Group Inc's (FPL.N) Florida Power & Light Co, sending the solar cell maker's shares up more than 15 percent.

The 25-megawatt plant, which will be located in DeSoto County and completed in 2009, will use SunPower's technology that tilts the solar modules to track the sun as it moves across the sky. It is part of FPL's plan, announced late last month, to build 110 MW of solar power plants in Florida as it works to expand its renewable energy output.

FPL already has the most installed domestic wind generation among U.S. companies.

Financial details of the SunPower contract were not released, but FPL said last month it would pay $688 million for all of its solar projects.

SunPower will also build a 10-megawatt solar power plant for FPL at the Kennedy Space Center that will be completed in 2010.

"These agreements confirm the growing trend in the U.S. to build solar power plants at a scale rivaling those in market-leading countries such as Germany and Spain," Howard Wenger, SunPower's senior vice president, said in a statement.

SunPower is the North American market leader in solar photovoltaic, which turns sunlight into electricity inside solar cells.

Currently, the largest single photovoltaic power plan in North America is the 14-megawatt installation at Nellis Air Force Base in Nevada, which was built by SunPower.

SunPower shares were up $9.73, or 15.9 percent, at $70.96 in afternoon trading after, hitting a high of $71.38 earlier in the session. (Reporting by Nichola Groom and Matt Daily; Editing by Derek Caney and Andre Grenon)