UPDATE 3-Electronic Arts buys social game maker Playfish

* EA pays $275 mln in cash plus other consideration

* Playfish hits like "Pet Society" are on Facebook, iPhone

* EA shares closed up 2.79 percent (Adds comment from venture capitalist)

By Franklin Paul

NEW YORK, Nov 9 (Reuters) - Electronic Arts Inc (ERTS.O), maker of the "Madden NFL" series of video games, bought venture capital-backed Playfish for $275 million in cash plus other consideration, seeking to expand into the growing social gaming sector.

The two-year-old Playfish, whose investors include Index Ventures and Accel Partners, makes games for people to play on computers with friends, unlike traditional video games that need dedicated consoles such as Microsoft's (MSFT.O) Xbox or Sony's (6758.T) PlayStation.

London-based Playfish's hits include the game show-styled "Who Has the Biggest Brain?" and virtual pet game "Pet Society," which boasts some 21 million users a month.

The games are free, but players can buy or give virtual goods -- such as flowers, clothes, furnishings and weapons.

"The great thing about games is people play and pay for games -- what we are seeing change is the model in which they are doing so," said EA Interactive executive Barry Cottle.