Changing roles and scene characterize today's financial marketplace

To measure financial services today is a bit like taking a snapshot. You can freeze a frame, but the scene goes on changing. Right now, the photo of the financial-service leaders shows this:

* Shearson/American Express is ahead in credit and travel services. It is strong in securities and insurance.

* Merrill Lynch dominates securities and cash-management and is increasing its strength in real estate.

* Sears is ahead in insurance (and, of course, in housewares), a leader in real estate, and No. 2 in cash-management.

These and most other major brokerage concerns (Prudential-Bache, E.F. Hutton, Paine Webber, Smith Barney, Kidder Peabody, Advest, Fidelity, etc.) are racing to provide more services and garner more clients. They are doing so on the territory once exclusively controlled by America's banks. And now banks - with their market-rate accounts, discount securities services, and tremendous capital and expertise - have been unleashed to compete.

Next year's snapshot undoubtedly will show new faces.

Shearson/Amex has been experiencing huge increases in earnings with the year-old bull run of the stock market. The broker-age component's earnings gain in the first half of 1983 was $56 million, up 126 percent. Fireman's Fund is the affiliated insurance company, and the parent, American Express, is the well-known credit/travel/travelers-check giant. Real estate ventures are handled by Balcor/Amex, an investment management and mortgage banking company that offers, for the more sophisticated investors, syndicated real estate partnerships

Shearson/Amex does not see itself as a financial supermarket. Agents are not simply middlemen, says Mary McDermott, a first vice-president. They are professionals, trained to treat the ''whole client'' as a lawyer or accountant would. Brokers in Shearson/Amex parlance are ''financial consultants.''

Upward of 200 financial products are employed, ranging from stocks and bonds to commodity futures. Shearson/Amex packages services in a Financial Management Account. With a $15,000 opening balance, this sweeps client assets into a money-market fund; at the same time a client is given a securities-trading and margin-loan account, issued an American Express Gold Card, and given checking privileges. All this is tracked in a comprehensive monthly statement of net worth.

Shearson/Amex's top competitors in consumer-level financial services (as opposed to financial services for the wealthier) are Merrill Lynch and Sears.

Account executives at Merrill Lynch sell more than 100 financial products, from overall cash management accounts (similar and antecedent to the Shearson/Amex FMA) to stocks, mutual funds, and such esoteric items as options on stock indexes. While Shearson/Amex and Sears offer the most varied services to customers, Merrill Lynch, without doubt, has been the most innovative at devising new financial products, having devised the revolutionary Cash Management Account in 1977.

One million customers have signed up for this account, making it by far the industry leader. It was four years before its competitors offered similar services and only last year before banks were allowed to compete in this area with money-market funds. Though competitors are now in the act, Merrill Lynch is so proud of its development of the CMA that it has filed suit against brokerage firms that have copied it, claiming infringement of patent rights.

Merrill Lynch also increasingly is involved in real estate. Merrill Lynch Realty Associates consists of 32 local real estate brokerages, the most prestigious component being added with the acquisition of the Paula Stringer Agency of Dallas. This makes Merrill Lynch the largest real estate broker in the country (ubiquitious Century 21 is a franchise operation) and a leader in the relatively new business of corporate relocation management. Merrill Lynch Hubbard is a commercial broker, buying and selling space in shopping centers and office buildings such as New York's World Trade Center. Merrill Lynch Family Life Insurance is a mortgage guarantee company.

''We have moved in this direction,'' says Merrill Lynch spokesman William Clark, ''because we believe in the long-run real estate will come alive again.''

Merrill Lynch's edge on the financial-services market comes primarily from its long-term, recognized strength in the brokerage business. With 10,000 account executives (brokers) in 450 branch offices of its Individual Services Division, Merrill Lynch has reach. That makes it one of the most accessible of financial-service outlets. Even so, a potential customer still may see a Merrill Lynch office more as a brokerage firm than as a full-service financial center.

This is where a company like Sears with its real estate, stock-brokerage, and insurance divisions may have an edge.

There are more than 700 Sears stores throughout the country. In many of them now there are desks for Allstate Insurance, Allstate Savings, Coldwell Banker real estate, and Dean Witter Reynolds securities. In the area of cash-management accounts, Dean Witter is Merrill Lynch's closest competitor. In real estate, Coldwell Banker is a giant. Allstate is the country's second largest insurer. Sears expects to have 250 one-stop financial centers established in its stores by the end of 1984.

At the least, Sears stands out in a financial-service industry that looks more and more homogeneous. In layout of merchandise and services, it is the closest thing around to an actual supermarket.

But in all fairness, says Ms. McDermott of Shearson/American Express, if you are comparison shopping in the financial-services supermarkets, you ought to remember that competition is intense. Thus it is virtually certain that what one financial-service company has today will be duplicated tomorrow by its competitors.