The United Way of America raised $2.1 billion this year, a 10 percent increase over last year, but proposed tax reforms could "cripple" future fund efforts, UWA Chairman Robert A. Beck said yesterday. And that could cost United Way, he said, as much as 20 percent in annual contributions.

Contributions were up in the Washington area, which raised $43.5 million, a 12.2 percent increase over last year, he said.

The United Way of the National Capital Area ranked seventh among the nation's 2,200 local United Ways. The New York city area was first with $135 million in donations.

Noncash corporate gifts to United Way also are growing through its Gifts in Kind program, Beck said.

Since the program began in January 1983, eight major companies have contributed goods worth over $16 million, Beck said. Recent gifts included 30,000 reconditioned Electrolux vacuum cleaners and 100 Apple computers, which United Way distributed to agencies that needed them.

Beck warned, however, that Treasury Department tax reform proposals would have the effect of eliminating the charitable deduction for low- and middle-income Americans who use the short form for their tax returns and who traditionally support the United Way.