ROCHESTER, Mich., July 11 - John W. Snow, the chairman of the private equity firm that is buying Chrysler, said Wednesday that a Senate bill to significantly raise fuel economy standards could devastate the American auto industry.

Mr. Snow said he was optimistic, though, that lawmakers would ultimately agree on a less stringent way to reduce dependence on imported oil. He said his company, Cerberus Capital Management, would fight the Senate measure because it intended to own Chrysler long term. Chrysler lost $1.5 billion last year and is cutting 13,000 jobs in efforts to reverse a long decline in its share of the United States vehicle market.

"We're committed to Chrysler; we're committed to making it an enormous success," he told a Detroit Economic Club audience here. He also said that Cerberus had no plans to sell Chrysler or to take it public after making it profitable again.