Prince George's County, often overlooked in conversations about so-called prestige locations in the area's booming economy, is trying to dress up its image and "go international" to attract more overseas, national and local business to its pastures.

The county, in an effort to erase the image of a sprawling, mainly warehouse district when compared with sister counties in Maryland and Virginia, has embarked on a major campaign and is already discussing possible relocations in the county with companies from Japan, England and Germany, according to Dennis Murphy, county economic development coordinator.

"Prince George's has been a sleeper in the past," Murphy said. "But we're coming into our own."

The county has a lot to overcome. It is viewed as a haven for the poor and has the lowest per capita income of the surrounding jurisdictions.

Prince George's also must dissolve the impression that nogrowth is policy -- an idea fostered by a seven-year sewer moratorium lifted less than two years ago. Before that, the county was glutted with apartments rather than the fancy homes business executives would like.

Even a recent report issued by the county Department of Program Planning and Economic Development said the county "has not established a strong regional identification as a focal point of office building construction and/ or demand."

Commented George Smith, a county economist: "Office development traditionally... focused in downtown areas. "When it moved out, it moved toward Montgomery County and Northern Virginia."

The sewer moratorium, imposed by the state when overflows at sewage treatment plants became almost daily occurrences, was partly to blame for the country's poor growth, Smith said. "A lot of people who may have had the desire" to locate in the county "were severely handicapped," he stated.

Now, the county is turning away no one while targeting its efforts on a major advertising campaign that will seek to lure foreign and national investments for firms in research and development, computer plants, manufacturing, office space, printing and technical fields, Murphy said.

Selling points to be emphasized will be the county's proximity to Washington, as well as Baltimore, highways and airports and a central location along the Eastern seaboard, Murphy said. Plenty of land for development is available, and the price of it is relatively cheaper than in the District or the other suburban areas, he added.

The county boasts that 2 million square feet of office building constuction will be added within a year. Currently, Prince George's has less than 5 million square feet of such office space compared with about 16 million in Montgomery County, 15 million in Northern Virginia and about 50 million in the District, Smith said.

During the past three years, 79 firms have either relocated to the county or expanded within, increasing employment by 3,000 jobs and new plant investment by $36.3 million. The Washington Business Park, opened in June 1976, has since attracted 28 businesses to the area, a recent county report said.

Some of the county's major businesses include the Hechinger Co., Giant Food Inc., Computer Science Corp., Merkle Press, Murray's Steaks, Suburban Bancorporation and M. S. Ginn Co.

International businesses may want to move to the county, partly from their general desire to expand markets in the United States, Murphy said.

The devaluation of the dollar abroad also is an incentive for foreign business to move here. Besides bringing more prestige to the county, an influx of national and international businesses will mean more jobs.

Few foreign companies have located offices or plants in the metropolitan area to date, but economists have said that with a desire to expand markets, that will change.

The Mercedes Benz company announced recently that it will be opening a plant in Hampton, Va., and Volvo of America has already built a plant in Chesapeake, Va. Volkswagen of America is producing Rabbits in Western Pennsylvania.

For several years, the State of Maryland has had an office in Brussels to promote business for the state, and Murphy said the state now is considering opening an office in Japan.

Virginia Lt. Gov. Charles S. Robb said yesterday that his state should "station a state representative in Tokyo," not only to increase imports and exports but to "assist foreign firms interested in plant location in the Commonwealth... Today we're talking primarily about Japan. Tomorrow, our sights could be extended to include the Republic of China."

Prince George's County economic developers are singing the same tune. They know they face competition and that a healthy economy cannot be guaranteed. While conceding that problems were evident in past performance, the county's new economic development program emphasizes the following:

More county residents are employed than at any time in history, with jobless rates below state and national averages.

Increases in personal income have far exceeded national averages, and the county now ranks in the top 5 percent of all U.S. counties.

There is evidence of a "resurgence of reinvestment in existing commercial areas... in terms of upgrading or expanding facilities."