*Masdar building largest Middle East solar power plant

*First Solar to supply half of plant's panels

*First Solar shares rise as much as 6.5 pct

ABU DHABI, Jan 15 (Reuters) - Abu Dhabi's Masdar said on Thursday it is building the Middle East's largest solar power plant for the carbon-neutral Masdar City.

Half of the 10 megawatt photovoltaic plant's solar panels will be supplied by First Solar Inc (FSLR.O: Quote, Profile, Research), the U.S.-based company said in a statement. Its shares rose 6.5 percent following the announcement.

The $22 billion Masdar City -- the green city in the desert -- will be home to 50,000 people and 1,500 businesses. No cars will be allowed.

First Solar's thin film solar panels are cheaper to produce, but generate less electricity, than traditional silicon-based solar panels. The remaining 5 MW of Masdar's solar power plant will be built from crystalline silicon panels. The supplier is yet to be named.

"While a 5 MW order is small within the context of First Solar, the high profile, 'marquee' nature of this particular project gives it added significance," Raymond James analyst Pavel Molchanov said in a client note.

The $50 million solar plant will begin producing power in 2009 and will supply any excess energy to the Abu Dhabi power grid, Masdar said.