Read the marketing literature of economic development agencies in the Washington-Baltimore region and you're likely to find only limited information about investment opportunities for manufacturing or wholesale distribution. Business attraction programs developed by those agencies typically feature investment opportunities in the services industry and related success stories.

While that may indicate shortcomings in the economic development programs of the various political subdivisions, it is indicative, nonetheless, of the importance of the services sector to the region's economy.

Still, business and government leaders may be shortchanging the region's economy by ignoring the market potential for other growth industries. That's the implication at least of recent studies of the investment potential in the Washington-Baltimore market. Those studies make a fairly strong case in favor of augmenting the region's service-oriented economy through more aggressive marketing focusing on opportunities in manufacturing and distribution fields.

There's no question that the services sector is the strongest component of the region's economy. In the Washington area, the services sector has been expanding much faster than it has nationally for more than two decades. Locally, employment in the services sector grew by nearly 30 percent between 1977 and 1982, compared with 19 percent nationally. Service industry employment now accounts for more than half the private-sector jobs in metropolitan Washington.

In the Baltimore area, meanwhile, the employment base has shifted significantly in recent years, from manufacturing to services -- the popular generic term for a wide range of employment categories, including business services, health care, legal services, eating and lodging, and personal services.

Small wonder then that the Washington-Baltimore region has emerged as one of the leading office construction and leasing markets. Strong demand for office space in the region is driven primarily by expansion in business and legal services and professional and trade membership organizations.

Compare the services sector with manufacturing or wholesale trade in the Washington area and it immediately becomes apparent why business leaders and government officials tout services as the backbone of the local economy. The services sector employs more than 643,000 persons, while there are only 86,000 manufacturing jobs in the area. The real strength of manufacturing as a component of the Washington-area economy can be measured by the fact that printing and publishing account for nearly half of the employment in manufacturing.

A suggestion that local governments should strengthen their employment base by pursuing investments in manufacturing and other blue-collar categories might have been interpreted as something akin to heresy as recently as two years ago. Increasingly, however, such recommendations are finding more receptive audiences in the Washington-Baltimore region. When put in the context of market potential -- the addition of billions of dollars and thousands of new jobs to the region's economy -- the argument tends to be more persuasive.

At least that was the impression that could be gotten from reactions among several executives who attended a business outlook forum held last week by the Washington-Baltimore Regional Association. According to the WBRA, the forum was designed to provide an in-depth look at market trends and growth industries in the region. For instance, executives who attended the forum heard another strong appeal for creating a leading biotechnology center in the region, but realistically the full bloom of biotech is years away. Even one of the panelists at the forum conceded as much.

On the other hand, the region's strong labor pool, outstanding education system and excellent transportation network create a favorable environment for manufacturing, according to Charles E. Cobb Jr., assistant secretary of Commerce, who urged executives to consider expansion in that sector.

Similarly, wholesale distribution, one of the so-called low-tech industries, could be a bonanza for the Washington-Baltimore region, implied L. Clinton Hoch, a leading authority on site selection for corporate headquarters, distribution centers and manufacturing facilities. Despite its "ugly duckling" image, Hoch said, wholesale distribution can "lay the golden eggs" in the region's economy.

Hoch reached a similar conclusion in a study for the WBRA last year. After more extensive research, however, he concluded in his presentation last week that the market potential for merchant wholesalers in the Washington-Baltimore region is 3 percent of the total U.S. consumer market and 2 percent of the U.S. industrial market.

Even though the Baltimore-Washington region ranks as nation's the fifth-largest retail market, its ratio of wholesale sales to retail sales is 1.23 to 1. Nationally, the ratio is 1.90 to 1. According to Hoch, this statistical "shortfall" indicates a potential in the region for annual wholesale sales of $17 billion. Such an increase would add 49,000 new jobs to the economy and would require the addition of 49 million square feet of new warehouse, showroom and office space in the region.

The region's market potential obviously will increase as the burgeoning retail sector expands, necessitating changes in the present distribution network. In the meantime, wholesale distribution centers in New York, Richmond, Philadelphia and Atlanta are sharing in the $17 billion in potential sales Hoch estimated this market is missing.

To concede that much money, jobs and real estate investment to other metropolitan areas implies a great deal more than confidence in the present structure of the region's economy.