In its report to stockholders a year ago, the management of General Electric Co. observed that GE "is not merely in the electrical business, or any other particular business."

"We are in the business of creating businesses to anticipate and serve the needs of a changing world," GE said.

Twenty years ago, 80 percent of GE's earnings were generated from the manufacture of electrical equipment for industry and the home. Although they still provide substantial revenue and income, "these traditional core businesses provide less than half of our earnings," John L. Ingersoll, GE's corporate-investor communications manager, told security analysts last fall.

More than half of GE's earnings now come from rapidly growing businesses involving man-made materials, natural resources, medical systems, credit and information services.

Indeed, information services is "really one of the stars of General Electric's portfolio," said Gregory J. Liemandt, chairman and president of GE Information Services Co., in a recent interview.

GEISCO has also been one of the best-kept secrets in the vast spread of GE business segments, Liemandt added during the interview in his Rockville office.

From its beginnings as a fledgling part of GE's computer business, GEISCO has developed into what is believed to be the largest computer services company in the world.

GEISCO generated about a half billion dollars in sales last year and expects to do at least $700 million this year, said Liemandt.

"We've been growing at an annual rate of over 25 percent over the last several years. We're going to be a billion and a half dollars by 1986. We're going to hit the billion-dollar mark by 1984." ales in the lucrative computer services market have grown to more than $10 billion annually. Liemandt projects an annual growth rate of 20 percent for the industry for the near term.

If GEISCO is one of GE's best-kept secrets, the secret is shared by a long list of Fortune 500 companies. Thousands of companies throughout the world use GEISCO to solve a broad range of computer-related problems.

In fact, about 80 percent of GEISCO's revenues are generated from services it provides for companies on the Fortune list of the 1,000 largest, and the top 300 banking and financial companies, said Liemandt.

On the other hand, despite being one of the largest companies to be based in Montgomery County, GEISCO has managed to maintain a fairly low profile at its two Rockville locations, which have a total of more than 300,000 square feet.

GEISCO employs more than 5,000 in its worldwide operation, which includes a network of more than 500 processing and communications computers. About 1,200 of those employes work in metropolitan Washington.

GE developed the computer time-sharing concept in conjunction with Dartmouth College in 1964. Basic time-sharing is still a "very important product," but GEISCO is now a "computer services supermarket," Liemandt says.

GEISCO's other services include batch processing and custom software design. Companies can buy raw computer power from GEISCO, "canned" or custom-designed software from its vast library of 200 programs, or consulting services.

It employs more than 1,500 software experts around the world and, according to Liemandt, the demand for additional personnel is growing.

Where customers are concerned, competitive pressures have heightened demands for timely information and better financial planning and the need to expedite problem-solving.

"Customers don't have the people, they don't have time, and we can help them," Liemandt said.

What's more, he said, "We are driven by one fundamental demand relationship: There is a severely inadequate supply of programmers."

From its nine-floor "supercenter" in Rockville and two others in Ohio and the Netherlands, GEISCO has a massive capability to provide computer power to its clients.

With its processing computers and data transmission and distribution links, GEISCO provides computer services to its customers 24 hours a day.

But the key to GEISCO's future growth lies in what Liemandt calls "value-added services."

To support the value-added services growth strategy, GEISCO last year expanded its capability with the acquisition of four software companies. One of the recently acquired companies, Banking Systems Inc. of Dallas, is a leading supplier of software for automated and manned-teller activities, bill payment transactions and data entry functions.

Banking Systems was acquired along with:

Software International Corp. of Andover, Mass., a leading producer of packaged software for accounting, financial and manufacturing applications.

Energy Enterprises of Denver, producers of accounting, production monitoring and evaluation systems for the oil and gas industry.

Earlier last year, GEISCO acquired Lamda Technology Inc., a New York-based supplier of custom software services.

Those companies are expected to play a major role in GEISCO's goal of building what marketing Vice President Arthur J. Marks calls "target markets of opportunity."

The focus will be on banking, manufacturing and energy, Marks said.

Although GEISCO's revenues are generated from a wide customer base, it's "still important for us to develop certain niches," said Marks.

And while competition in the computer services industry is expected to get tougher, it won't have an adverse effect on GEISCO, Marks indicated.

"Once you develop a customer's needs and establish a relationship with a client you become almost a part of that company," he said.

With the demand for computers soaring (an estimated 5.4 million will be in operation by 1985) the need for programming and software services can be expected to rise accordingly.

"When you tell me that businesses are going to slow down their use of computers I'll tell you when we're going to slow down," Liemandt said.