Tension is mounting between BP and the neighborhood retailers that sell its gasoline.

As more Americans shun BP gasoline as a form of protest over the Gulf oil spill, station owners are insisting BP do more to help them convince motorists that such boycotts mostly hurt independently owned businesses, not the British oil giant.

To win back customers, they’d like the company’s help in reducing the price at the pump.

BP owns just a fraction of the more than 11,000 stations across the U.S. that sell its fuel under the BP, Amoco and ARCO banners. Most are owned by local businessmen whose primary connection to the oil company is the logo and a contract to buy gasoline.

In recent weeks, some station owners from Georgia to Illinois say sales have declined as much as 10 to 40 percent.

Station owners and BP gas distributors told BP officials last week they need a break on the cost of the gas they buy, and they want help paying for more advertising aimed at motorists, according to John Kleine, executive director of the independent BP Amoco Marketers Association. The station owners, who earn more from sales of soda and snacks than on gasoline, also want more frequent meetings with BP officials.

“They have got to be more competitive on their fuel costs to the retailers so we can be competitive on the street … and bring back customers that we’ve lost,” says Bob Juckniess, who has seen sales drop 20 percent at some of his 10 BP-branded stations in the Chicago area.

Owners and distributors put forth their demands at a meeting in Chicago with BP marketing officials. BP’s reply could come as early as this week, says Kleine, whose group represents hundreds of distributors.

Station owners are locked into contracts that can last seven to 10 years in some cases. So, switching to a competing brand if BP refuses to help may not be an option.

Websites and Facebook pages advocating a BP boycott popped up soon after oil started spewing into the Gulf in late April.

The biggest hit for store owners comes not from lost gas sales but from lost convenience store business. Owners make just pennies on a gallon of gas. But they might make up to 55 cents on a $1 cup of coffee. The margins on candy and chips are about 48 percent and 37 percent, respectively, said Jeff Lenard of the National Association of Convenience Stores.

The boycott’s impact on BP is limited. The company makes most of its money exploring and producing oil in places such as Angola, Egypt, the North Sea and the Gulf of Mexico.

And even if drivers opt to fill up at an Exxon or 7-Eleven, they still may buy BP gasoline. Because of the way gas is refined and marketed, BP fuel gets supplied to stations other than those with BP brands.