It's been a decade since Martin Marietta Corp. moved from New York to take up residence by the Beltway. And in that time, the area's largest company has assumed more and more of the characteristics of many of its neighbors.

Once an industrial conglomerate whose heavy aerospace bent was balanced by major involvement in such old-line businesses as cement, aluminum and sand and gravel, Bethesda-based Marietta has been transformed into a high-flying, high-technology outfit able to compete head-on in data processing, contract management and some of the other esoteric arts practiced by many of the companies that ring Washington.

Martin Marietta still builds rockets, missiles and other aircraft parts and equipment, but under the hand of Chairman Thomas G. Pownall, the company has shed most of its other businesses in favor of a strategy oriented toward faster-growing fields. In addition to data-processing and contract management, Marietta is dabbling in high-tech communications systems and biotechnology, and even has plans to go into the satellite business. More than ever, the company is placing priority on research and development work to develop new technologies.

"I think it is positioned to become a major growth company through the '80s," says Anthony Pearce-Batten, an analyst at Baltimore's Legg Mason Wood Walker Inc.

In many cases, Marietta has created large chunks of business from its existing interests. Its own computer needs begat the data processing company -- now doing $275 million worth of business a year. And its aerospace business begat the $684 million federal air traffic control systems development contract that is one of the gems of its recently formed communications and information systems unit -- a $200 million-a-year business. Marietta's ability to manage complex defense projects such as the Titan and Pershing missiles has given it a leg up in the lucrative contract-management game: Earlier this year, it won a contract worth as much as $20 million a year to run the Department of Energy's $2 billion-a-year nuclear energy research laboratory complex at Oak Ridge, Tenn.

These new businesses are growing fast -- revenue from the data processing unit will increase by about one quarter this year, and Conning & Co. estimates that potential new orders for Marietta's information and communciations systems business alone could be more than $2 billion over the next few years. While the reshuffling of assets has left aerospace to account for about three-quarters of the company's revenue, based on 1983 figures -- far higher than a few years ago -- growth in Marietta's other businesses undoubtedly will equal the size of the aerospace division within a few years.

The announcement last month that the company had signed an agreement in principle to sell most of its aluminum business to Comalco Ltd. of Australia for $400 million in cash and notes marked the end of the last major portion of Marietta's old-line business sectors. About all that remains is a medium-sized basic materials business -- making ingredients used in highway contruction, steel making and other processes -- that Pownall says is too profitable to touch.

Pownall is getting high marks from Wall Street analysts for his transformation of the company, just as he did for directing Marietta's tough defense two years ago against a takeover raid from Bendix Corp.

Marietta's makeover can be traced directly to the aftershock from that notorious corporate war. The company emerged from the month-long siege with $1.2 billion in debt and 39 percent of its stock held by Allied Corp., which had swallowed Bendix in the battle's climax after rescuing Marietta.

Pownall is frank about Marietta's situation at that point, in September 1982. "We were faced with the prospect of going under, if we weren't very careful," he says now.

In the wake of the merger fight, the company needed cash in a hurry. Those problems forced a hard look at what Marietta was doing with its resources, greatly accelerating the modernization and asset redeployment the company had already been contemplating before the Bendix battle.

The businesses found wanting included cement, industrial sand, and a small dye and chemical operation. All were sold or closed. But Marietta put off taking the ax to its aluminum division. It is now known that the company had been looking for a buyer or partner for the aluminum business for the past two years. But as recently as the company's annual meeting in April, Pownall was telling shareholders the aluminum business would continue to be a major part of the company.

Indeed, Pownall says, that was the intention. The aluminum industry was rebounding from its recent slump, and was doing well during the first part of this year. "We believed unhesitatingly that we had properly calculated out participation in the market and the prices that we thought we would receive, and believed that we had something between an $80 million and $100 million turnaround, going from a $50 million loss in aluminum to a $30 million or $50 million profit," Pownall says. "We were on that course until the market began to decay" in late spring.

Worried it would lose what value it had left in its aluminum business, Martin Marietta sold the operation to Comalco, a major player in the Australian aluminum market that was looking for an American position. Marietta also arranged to sell an interest in a California plant to Atlantic Richfield Co. and will try to sell its two other aluminum plants, Pownall says. If not sold, they will be closed next year, he adds. The company took a $365 million write-off on the aluminum operations, giving it a net third-quarter loss of $324 million.

When its pullout from the aluminum business is completed, Marietta will have about $500 million in additional capital and a big load off of its cash flow. Some of the money from selling the aluminum operations will go to pay down the remaining post-Bendix debt. Most of that, as well as Allied interest in Marietta, was paid off with proceeds from the sale of assets, with help from a strong stock market and improved interest rates that made it easy to get financing.

With the decks cleared of its highly capital-intensive businesses, Pownall hopes to plunge Marietta even deeper into the high-tech field.

A big chunk of the aluminum money will go to support research and development -- the company has already earmarked $250 million for R&D in the aerospace sector alone.

Analysts already give Martin Marietta points for buying stakes two years ago in three highly regarded biotechnology companies: Chiron Corp., of Emeryville, Calif., which is developing genetically based products for human use; Native Plants Inc., of Salt Lake City, which specializes in products for agriculture; and Molecular Genetics Inc., of Minneapolis, which is exploring uses of biotechnology for animal breeding and health. These investments come at a time when most other companies are keeping a cautious eye on that fast-moving field. If one of the three companies makes an important discovery, Marietta's holding could turn into a gold mine.

But much of the company's high-tech growth will come from businesses it already knows, and it is committing some of the aluminum money to expanding those through acquisition or internal development.

The data processing division, which has its origins in the computer needs of the aerospace business, now provides software and services to a variety of outside customers for uses in computing and managing payrolls, finances and personnel matters. Last year, Marietta purchased Mathematica Inc., a fast-growing software house, to add to the data processing division, and Pownall would like to make additional acquisitions in the field. Combined with natural growth of the data processing industry, the Conning report estimates the data processing division could generate more than $1 billion in sales by 1988.

The information revolution also is fueling Marietta's fast-growing communications and information services division. Formed last summer from operations in the aerospace and data processing divisions, the business covers several military and commercial fields, including "command control communications and intelligence," the tongue-twisting designation for sophisticated military command systems.

The communications and information systems division is managing Marietta's participation in a $684 million, 10-year contract to revamp the Federal Aviation Administration's national air traffic control system -- which the company hopes will give it the expertise to sell similar systems to foreign governments.

The FAA contract is an example of one of Marietta's chief skills: managing large government contracts, something it's been doing for years in its rocket and missile work. Similarly, the company is applying those skills to running the Oak Ridge facility for the government. That job, which is covered by a separate subsidiary, also encompasses funding some small startup high-tech businesses in the Oak Ridge area, as well as the development of an industrial park there.

Marietta hopes to spin off enough technology or business from the Oak Ridge project to fuel another whole area of growth. "There's an immense talent base down there," Pownall says. ". . . We've got to learn something."

The FAA and Oak Ridge jobs, Pownall says, are the kind of management contracts he wants Marietta to pursue -- ones that offer the possibility to develop new business opportunities. Otherwise, he says, the company does not expect contracts for the management of government installations to be a major part of Marietta's business.

So far, the emphasis on finding business that can create other business has been good for Marietta, and the company is now putting the same sort of analysis into creating new lines from its older businesses. Realizing it was building satellites and rockets for others to use without getting full benefit, Marietta now is planning to keep some of the action for itself. It has applications pending before the Federal Communications Commission to build, launch and operate a pair of communications satellites that it would lease for data, voice and video transmissions.

But even as Pownall propels Marietta into a high-tech future, the company is holding on to a little of its low-tech past. Aluminum, cement and sand may be history at Martin Marietta, but Pownall says he's not about to part with the basic materials business, which ranges from sophisticated asphalt patches and crushed stone and gravel for highway construction, to magnesia products used in steel making and other processes. The division is extremely profitable, contributing $90.8 million to Marietta's 1983 operating earnings. Pownall would like to acquire more small companies in the basic products fields.

"It would be hard to find something to replace it with," he says. "You may find something that's a lot sexier, a lot more technologically sophisticated, a lot more fun to work with, but trying to find all those things in something that can equal what we're getting out of [that division] is going to be kind of tough to come by."