Customers could lose as much as $233 million in the failure of the Bevill, Bresler & Schulman Asset Management Corp., according to Saul Cohen, the trustee for the failed government securities firm.

But Cohen said yesterday that a related brokerage firm -- Bevill, Bresler & Schulman Inc. -- has $42 million in assets that might be used to reduce losses of the government securities firm's customers -- most of them savings and loan associations.

The biggest loser of all could be a commercial bank, however. Worthen Bank & Trust Co. of Little Rock, Ark., said it could sustain up to $52 million in losses, enough to wipe out its capital.

But regulators said the bank is in no danger of failing. Its parent company has $110 million in capital -- some of which it would transfer to the bank -- and the bank has agreements with shareholders to buy additional amounts of stock. The Office of the Comptroller of the Currency has ordered the bank to maintain its capital at a level equivalent to 5 1/2 percent of its assets, which totaled about $1 billion at the end of 1984.

Worthen -- like nearly all the losers in the Bevill, Bresler failure -- left securities with Bevill, Bresler that the firm apparently used for its own purposes.

Cohen said he has found about $42 million in free assets to satisfy roughly $275 million of claims by customers of Asset Management Corp.

Government sources said savings and loan associations may have losses that are larger than the value of the securities they gave to Bevill, Bresler as collateral for loans from the securities dealer. Because lenders generally demand that the value of the securities be more than the loan, the S&L would lose the difference between the cash it has from Bevill, Bresler and the value of the securities.

But many of these securities were purchased years ago when interest rates were lower, and thus have a market value -- and therefore a collateral value -- that is less than their face value. Regulators permit savings and loans to carry the securities at face value on their books, however.

A spokesman for the Federal Home Loan Bank Board said the regulatory agency is looking into the impact of Bevill, Bresler's failure on the score or more of savings and loans that did business with the firm. But the spokesman would neither confirm nor deny that Bevill, Bresler-related losses might wipe out the net worth of one or more S&Ls.

When E.S.M. Government Securities Inc. failed last month, a privately insured S&L in Ohio was wiped out and its losses were so great that they absorbed all the assets of the Ohio insurance fund, too.

Yesterday the trustee for E.S.M., Thomas Tew, filed suit in Fort Lauderdale in an attempt to get back $45 million from American Savings & Loan Association of Florida.

Tew charged that American -- which had interlocks with E.S.M. -- unwound some of its investments before E.S.M.'s failure in what Tew called a "fraudulent and preferential transfer."

Meanwhile, legislation to regulate government securities dealers was introduced yesterday in the House by Rep. John D. Dingell (D-Mich.) and eight co-sponsors. It would bring the market under the same type of self-regulatory organization that now oversees the municipal bond market. Renamed the Public Securities Rulemaking Board, it would subject government securities dealers to inspections, disclosure and capital adequacy requirements.

Today the Securities and Exchange Commission, which was ordered by Congress to join with the Federal Reserve and the Treasury in coming up with ways to curb abuses in the government securities market, will ask for public comment, including cost effectiveness, on various alternatives, such as self-regulation or policing by the SEC or the Federal Reserve and whether voluntary capital requirements are sufficient.