The Securities and Exchange Commission yesterday fined Siebel Corp. $250,000 and imposed cease-and-desist orders on two other companies in the agency's first enforcement of a rule requiring that companies disclose key information to all investors, not just a few.

SEC officials said the fine against Siebel -- and the cease-and-desist orders to Secure Computing Corp. and its chief executive, John E. McNulty, and to Raytheon Co. and its chief financial officer, Franklyn A. Caine -- demonstrate the agency's seriousness about upholding what is known as Regulation FD (for "full disclosure"). The rule, which was decried by officials of many publicly traded companies when it was adopted in 2000, says that if a public company is going to disclose important, nonpublic information, it must do so to everyone rather than selectively.

The goal was to put all investors on equal footing rather than letting investment bankers or large institutional shareholders trade on valuable information ahead of others.

In the Siebel case, a company official told an invitation-only meeting of investment bankers in November 2001 that the company's business was picking up. That contrasted with "negative comments" he had made publicly a few weeks earlier, an SEC lawyer said. The company's stock rose more than 20 percent the next day, and SEC enforcement officials said they were able to trace trading profits to people who had been in the audience.

At Secure Computing, an official disclosed the existence of a major contract to two institutional shareholders before the company announced it to the public. The disclosure problem at Raytheon was similar, SEC officials said.

The companies agreed to the SEC actions without admitting or denying guilt.

The SEC said it also had investigated Motorola Inc. because an official called a handful of Wall Street analysts to give them details that the public didn't have about the company's sales and orders. The agency took no action because the official broke the disclosure rule inadvertently, after receiving a green light from a company lawyer.

But the agency issued a report intended to alert other companies against doing what the Motorola official did.

The five-member SEC split over the enforcement actions. Two of the three Republican commissioners, Paul S. Atkins and Cynthia A. Glassman, voted against imposing a fine on Siebel, arguing the penalty was inconsistent given that the other two companies weren't fined.

One of two Democratic commissioners, Roel C. Campos, voted against cease-and-desist orders for Raytheon and Secure Computing, arguing that they should have been fined.

Only two commissioners, SEC Chairman Harvey L. Pitt, a Republican, and Harvey J. Goldschmid, a Democrat -- who have been at odds for weeks over how the SEC is run -- voted together in favor of all the enforcement actions.

"These are very straightforward cases," said Michael R. McAlevey, a lawyer at Alson & Bird, who when at the SEC from 1998 to 2001 helped write the regulation. "The SEC repeatedly said it would not go out on a witch hunt. Regulation FD was a controversial rule, but most people don't view it that way anymore. Most people have learned to live with it."