On Tuesday, the commission disclosed that a nine-month investigation had found widespread evidence that brokers received undisclosed payments for steering investors toward specific funds.

But on Friday, the commission quietly disclosed it was abandoning the rules.

Only a few days earlier, however, the commission had disclosed that it is considering waiving its requirement that local governments participate in emergency planning.

The commission had disclosed the scheme in hearings in January.

These commissions varied but disclosed a broad line of uniformity.

Today, the commission disclosed its own estimate, 13 years, which it decided was too long to justify closing the lab.

The commission discloses investigations only if it finds "reasonable cause" to believe that someone has violated the ethics rules, said Walter C. Ayres, its director of communications.

The commission has not disclosed the position it would take in the brief.

The commission disclosed what had happened then, in great detail.

Neither the company nor the commission would disclose the filing's contents.