LOS ANGELES, AUG. 10 -- Democratic gubernatorial candidate Dianne Feinstein has launched a major assault on her Republican opponent, Sen. Pete Wilson, on the savings-and-loan issue, further fueling a negative television campaign escalating here much sooner than expected.

A new 30-second Feinstein advertisement appeared without warning Wednesday saying that "savings and loan executives gave Pete Wilson $243,000, more than any other member of Congress" and that he "voted to hide the S&L bailout costing taxpayers an extra $4.5 billion."

Wilson, armed with editorials and newspaper articles declaring him innocent of blame in the savings-and-loan scandal, immediately attacked the Feinstein spot as "character assassination" and "McCarthyism" and derided her earlier promise to refrain from a negative campaign.

As a measure of how difficult the issue's size and complexity is for both political parties, Wilson aides gleefully noted an article in today's San Jose Mercury-News saying Feinstein had benefited personally from the scandal because her financier husband, Richard Blum, helped to buy a failing savings and loan at low cost and profited from subsidies under a federal rescue plan.

Feinstein's new attack followed an expensive run of Wilson ads debunking as "quotas" her call for matching state minority hiring to population ratios. Feinstein produced an ad responding to the charge, then decided that it was necessary to spend her relatively meager cash reserves on a new ad that would put her back on the offensive. Polls have shown their race to be very close.

"Sen. Wilson's duty to the citizens of California was not to sit by and watch as the S&L scandal unfolded," Feinstein, a former San Francisco mayor, said in a prepared statement. "And his excuse that he did nothing isn't good enough."

"However juicy the issue," Wilson told reporters Thursday, "she has got the wrong man."

A Wilson statement addressed itself to Feinstein: "You said to the media that there is no evidence that I did anything wrong, yet now you are using McCarthyism tactics to impugn my character. This is premeditated malice, making false charges, engaging in character assassination, and I call on you to immediately withdraw your ad."

The Feinstein commercial, which shows five "S&L Facts" over a picture of a pile of money, notes that Wilson received $9,000 in honoraria from savings and loans and alleges that he "voted against adding inspectors to protect us from savings-and-loan fraud." The ad concludes: "California can't afford a politician like Pete Wilson as governor."

Wilson said that Feinstein distorted reasons for votes mentioned in the ad and that he voted against the savings-and-loan industry's position on the two principal rescue bills. "What Feinstein is attempting is defamation," he said.