NEW YORK (AP) _ Someday, it may become commonplace for investors to buy a stake in a pool of assets that once belonged to a corporation or a bank.

Apart from mortgages, the practice has been fairly restricted so far. Securities backed by automobile loans have mainly attracted large institutional investors, like insurance companies, pension funds and savings and loans.

But brokerage houses have been eyeing all sorts of assets as candidates for ''securitization.'' Seminars are being devoted to the possibilities and benefits the practice could provide.

At First Boston Corp., one of the firms that wheeled out the first auto- loan-backed investment vehicles last year, a staff of about two dozen has been assembled to continue developing asset-backed securities.

The firm will soon release what it considers a comprehensive examination of the car loan-backed securities and officials there say it could become the ''bible'' of the asset-backed business.

Such securities are patterned after mortgage-backed securities, which were first developed by government agencies, such as the Government National Mortgage Association, in the 1970s.

Housing industry experts generally agree that the secondary mortgage market - the constant buying and selling of mortgage loans throughout the country - has helped lenders and homebuyers alike.

''It has dramatically improved the depth of the mortgage markets,'' said Edison Zayas, senior economist at the Mortgage Bankers Association.

He explained that lenders have greater access to funds and are more willing to loan them out because they know they can shed old loans from their books.

''The availability of funds is no longer a problem ... lenders don't have to depend on deposits as a source of mortgage funds,'' said Zayas. ''The mortgage market operates very smoothly because the securitization of residential loans has vastly improved the liquidity.''

From the consumer's point of view, the secondary mortgage market has made it easier for people to get money to finance the purchase of a home.

The market really took off during the recession in the early 1980s when lenders had to liquify their balance sheets, and, largely because the secondary market existed, they could continue making loans.

It has generally been assumed that the innovations in real estate finance, could be applied in other areas, Zayas said.

General Motors Acceptance Corp., for instance, has sold off packages of auto and truck loan receivables. It continues to service the loans, collecting payments and going after people who fall behind in payments.

GMAC guarantees that if there is a default of one of the loans they have sold in packaged form, it will cover the first 5 percent of the losses.

Underwriters say GMAC's deal gave the big car lender an alternative way to raise money, rather than borrowing in the commercial paper market.

By removing the loans from their balance sheet, GMAC does not have to keep reserves against them. Selling off the loans also enables the company to do more business without expanding its debt burden and also lessens its vulnerability to rising interest rates.

Ultimately, the car buyer stands to gain because the lender theoretically has enhanced its liquidity and may be able to offer loans at lower rates.

''Our feeling is that this practice is good for the companies that do it, so we think it will be good for the companies' customers,'' said Anthony V. Dub, a managing director of First Boston.

Beyond car loans, underwriters are said to be working on plans to sell debt backed by credit card receivables on the books of banks, which are assets because they represent payments due.

Salomon Brothers Inc. and others among Wall Street's powerhouses are developing the deals.

Banks could find the deals an attractive way to free up capital because the sales would reduce the asset base that federal regulators use to compute their capital reserve requirements.

Whether the banks' or similar deals will flourish is uncertain, in light of various regulatory standards that must be met.

But the underwriters expect the market in asset-backed securities to expand, and car loan-backed deals could reach $4 billion this year, about double last year's volume.

End Adv Weekend Editions March 22-23