The heads of five major brokerage firms testified yesterday the Hunt brothers of Texas have either paid off their silver speculation losses or put up more than enough silver to settle their debts.

The assurance that the billionaire brothers are no longer in serious financial trouble came from top executives of ContiCommodity Services, E. F. Hutton, ACLI International Commodity Services, Bache Halsey Stuart Shields and Merrill Lynch, Pierce, Fenner & Smith.

The five firms were asked the status of their Hunts accounts by Rep. Ed Jones (D-Tenn.), chairman of a subcommittee holding hearings on silver speculation. The hearing continue today.

The answer to Jones raised new questions about why the Hung brothers need the controversial $800 million loan they have negotiated from a group of banks with the approval of Federal Reserve Board Chairman Paul Volcker.

Setting aside his own policy of discouraging loans for speculative purposes, Volcker acquiesced to the Hunt loan. Fed officials have indicated they feared that if the Hunts defaulted on their loans, banks and brokerage houses might get in financial trouble and the fallout would ripple through the whole economy.

Details of the loan agreement have been completed, and the Hunts are expected to begin using the $800 million shortly, bankers involved in the transaction reported this week.

Even without using the loan, the Hunts have paid off all their obligations to Bache, said Fred Horn, senior vice president in charge of commodities. Hutton and Conti officials said the Hunts owe them no money.

Spokesmen for both ACLI and Merrill Lynch told Jones the Hunts owe them money but, as Merrill vice president Jerome Spielman put it, the loans "are in satisfactory condition."

Neither company revealed how much the Hunts owe them, but sources familiar with the loans say Merrill Lynch loaned the Hunts even more money than Bache, which at one point loaned the Hunts 233 million.

The Hunts put up silver as collateral on the loans from the brokers and, even after silver prices fell from $50 to around $11, the silver is worth more than the Hunts owe on the loans, the brokers' testimony indicated.

All five brokerage house executives admitted it is not common practice for them to lend money to customers.

"We're not bankers, we're merchants," said Henry Maringer, president of the ACLI commodity operation, a subsidiary of ACLI International Inc., which is owned by Adrian C. Israel, chairman of People's Drug Stores.

But ACLI's parent company did lend money to the Hunts to buy silver, and so did Merrill Lynch, and Spielman said "it would be unusual" for the big broker to make such loans.

Committee members criticized Bache for lending money to the Hunts, who also owned more than 5 percent of the stock of the company. Securities and Exchange Commission member Irving Pollack said the SEC is investigating the relations between Bache and the Hunts.

Rep. Frederick Richmond (D-N.Y.) rapped the commodity brokers for "obvious conflicts of interest" in the way rules for commodity markets are set. "

The same companies that handle commodity trading orders for the public also trade on their own, he noted, and the companies also elect directors who set the rules for trading.