The stock of Gardenburger Inc. rose 10 percent on reports its television advertising campaign has boosted sales of its vegetable burgers.

On Thursday, the Associated Press reported that the company may extend the ads, which began airing the week of May 11. The company, which is based in Portland, Ore., spent $1.7 million on a commercial that ran during the last episode of "Seinfeld" on May 14.Since then, sales have blossomed, and Gardenburger's chief executive, Lyle Hubbard, said the company is "very serious" about continuing the campaign.

The company employs 111 employees at its Clearfield plant in the Freeport Center.

Hubbard declined to say how much the company would spend on an ad extension, which needs board approval. So far, Gardenburger, which reported first-quarter sales of $13 million, has spent $10 million on the ads.

But the investment is paying off, Hubbard said. The company has captured a 50 percent market share of veggie burgers distributed in grocery stores for the week of May 23, compared with a share of about 31 percent the week before the ads aired.

Hubbard hopes to extend the ads to cover the key grilling season of July and August. The goal of the ads, he said, is to move the product to mainstream consumers from the "health niche" category.

Shares of Gardenburger rose $1.183/4 to $12.75 on Nasdaq Stock Market volume of 466,700 shares, compared with average daily volume of 122,700 shares.