For most of its 96-year history, Sears, Roebuck & Co. has stood for paint and appliances, clothing and catalogue sales.

On Monday, shoppers arriving at a Sears store in suburban Virginia will find a flashing electronic tickertape, welcoming them to "the new Sears Financial Network."

In a cluster of offices near the candy and nuts department, Sears will be selling and buying houses, stocks, bonds and money market funds, opening Individual Retirement Accounts and writing insurance for cars and homes.

The new Sears department in Fair Oaks Mall at the intersection of Rt. 50 and Interstate 66 in western Fairfax County is the first of a wave of "financial supermarkets" that will be opening in banks, stores and shopping malls in the coming decade.

Dozens of companies, most of them in one branch of the financial services industry, are making plans to broaden widely the kinds of products and services they offer customers in the belief that, as the financial world gets riskier and more complicated and the types of investments proliferate, shell-shocked consumers will find it easier to do all their financial business under one roof.

Insurance companies have bought brokerages. Bank of America is trying to buy a discount broker, and other banks are offering customers some brokerage services. A group of savings and loan associations, including Washington's Perpetual American, plans to open a brokerage subsidiary in September. American Express, whose green and gold credit cards as well as their travelers checks are household words around the globe, bought the nation's second biggest brokerage firm, Shearson Loeb Rhoades Inc.

Merrill Lynch & Co., the nation's biggest brokerage firm, started the move toward combining historically separate financial services: Merrill-owned firms buy and sell real estate, sell insurance and relocate executives. Merrill pioneered the so-called Cash Management Account, which permits well-heeled customers to earn high rates of interest on balances that used to remain idle on their brokers' books.

But Sears, the nation's largest retailer with more than 24 million credit cards, is the first company to put all its financial services firms under one roof. Whether the company can breathe life into the heretofore theoretical financial supermarket will be watched carefully by the rest of the financial services industry.

Sears is no stranger to that industry. It long has owned Allstate Insurance Co., one of the three firms that will share space in the Fair Oaks financial supermarket. But late last year, as part of a plan to become a major player in financial services as well as retailing, Sears bought Dean Witter Reynolds, one of the largest securities firms on Wall Street, and Coldwell Banker, a real estate brokerage and mortgage-banking firm.

Allstate, Dean Witter and Coldwell will share office space in Sears Fair Oaks, across from its customer service and catalogue department.

The financial supermarket will not operate on bankers' hours. The department will be open Monday through Saturday from 10 a.m. to 9:30 p.m. and Sunday, noon to five.

Fair Oaks is one of eight financial supermarkets Sears plans to open Monday. The others are in Atlanta, Dallas, Houston, Chicago, Denver, Los Angeles and San Francisco. Customers in California also will be able to make deposits and withdrawals at accounts at the Sears-owned Allstate Savings and Loan Association. Federal laws prohibit the savings and loan from doing a deposit-taking business outside of California.

Mel Wright, Dean Witter's senior vice president for the region, said brokers will alternate between Dean Witter offices in Northern Virginia and the Fair Oaks complex.

Wright said Sears will push its new operation with promotional inserts in the monthly bills of all Sears credit card holders in Northern Virginia and will do direct mailings to other residents who do not own Sears cards.

Virginians who live in the store's market area have the highest average income of any Sears store in the nation, the Dean Witter official said. Fair Oaks Sears shoppers have an average household income of more than $40,000 a year. That's several thousand dollars more than the second- and third-ranking stores in the wealthy Chicago suburb of Oakbrook and at the Sears Montgomery Mall store.

Sears officials said that the company has put its eight financial supermarkets in all types of market areas and will use different types of promotional programs to see what type of customers and how many are attracted to the new facilities.

At some stores, an official said, Sears will offer Cross pen and pencil sets to lure prospective financial clients. "At others we'll do nothing, we'll just let it sit there."

If Sears has any goals for profitability or customer traffic, the company is keeping them to itself.

"This is a unique experiment," Wright said. "I told my people that things we think are going to happen won't and that things we don't think will happen will. Here we go. We'll wait and sit back to see what happens. We'll do a lot of market research."