U.S. Proposal Seeks to Curb T-Bill Fraud : Securities: Plan would require those who hold $2 billion or more in a government issue to keep detailed records.

The Treasury Department is going to keep closer tabs on major buyers of government securities, hoping to prevent a repeat of the 1991 scandal involving Salomon Bros. Inc.

The Treasury published proposed rules Monday that would require those who hold $2 billion or more in any single government security--bonds, bills or notes--to keep detailed records and make them available to the department on demand.

The purpose is to help regulators determine whether any price distortions or shortages in an issue are due to manipulation, the department said. It said it will try out the system by selecting some of the buyers with holdings large enough that they report to the government at least once a year.

The new rules are an outgrowth of the scandal in which Salomon submitted false bids and controlled almost all of a two-year Treasury note. The law bars any company from buying more than 35% of a new issue.

Salomon agreed to pay $290 million in fines to settle charges of fraud and phony bookkeeping. The penalty is among the largest ever assessed in the securities industry.

The Treasury said the new rules are not unnecessarily burdensome but will help assure the public that the bond market is free of manipulation.