By Noel Randewich

SAN FRANCISCO (Reuters) - Shares of Craft Brew Alliance Inc <BREW.O> jumped 8.1 percent on Tuesday, bringing gains to 36 percent in the two weeks since the company announced a severance pay policy for executives in case of an acquisition.

The policy disclosed in a filing by the Portland, Oregon-based company, comes as thousands of small regional breweries pressure industry heavyweights already suffering from sluggish sales. Craft Brew is 32 percent owned by Anheuser-Busch Cos InBev SA.

Craft Brew, which sells Red Hook, Widmer Brothers and Kona beers, said in a filing on May 24 that in case of a change in control, it would pay each executive officer 18 months of their base salary, plus their annual target bonus and health benefits.

Executives who leave for reasons other than an acquisition would receive less generous severance, according to the filing.

The company did not immediately respond to a request for comment about its executive severance policy.

Kona, marketed as a beer to sip on a beach vacation, stands out in crowded craft beer market and has the best growth potential among Craft Brew Alliance's brands, said Sidoti & Company analyst Francesco Pellegrino.

"It's a craft beer that's going after the Corona market," Pellegrino said.

Thousands of U.S. micro breweries and brew pubs serving India pale ales, pilsners and stouts to increasingly discerning beer drinkers have become a major threat to Anheuser-Busch <ABI.BR>, SABMiller <SAB.L> and Heineken <HEIN.AS>.

U.S. craft beer sales jumped 16 percent to $22.3 billion last year and now account for more than one-tenth of total sales, according to the Brewers Association, an industry group.

Medium-sized brewers Craft Brew Alliance and rival Boston Beer Co <SAM.N>, which sells Sam Adams, have also felt the pinch from the proliferation of small competitors.

Analysts, on average, estimate revenues at Craft Brew Alliance will rise by 3 percent this year after a 5 percent drop in 2014, according to Thomson Reuters data.

Craft Brew Alliance's stock was last up 80 cents at $10.69, giving it a market capitalization of about $200 million.

(This version of the story corrects stock symbols for SABMiller and Heineken in the eighth paragraph and Boston Beer Co in the tenth paragraph.)

(Reporting by Noel Randewich; Editing by Jeffrey Benkoe)