United Technologies Corp., hoping to benefit from the Reagan administration's defense policies, has announced plans to combine two of its operations into a new Strategic Defense Systems division based in Arlington.

The new division, will begin operating Oct. 1, is a marriage of the firm's Strategic Defense Program Office in Arlington and the United Technologies Optical Systems (UTOS) unit in West Palm Beach, Fla. The division will sell its products -- including those geared toward the administration's Strategic Defense Initiative -- to the Department of Defense.

United Technologies, headquartered in Hartford, Conn., is best known for making Pratt & Whitney aircraft engines, Carrier air conditioning, Otis elevators and Sikorsky helicopters. The company is divided into five operating groups; the new division will be part of the Defense and Space Systems group.

"UTOS was in the UTC research center before," noted Gordon H. Sigman Jr., executive vice president and general manager of the new division. "We noticed that UTOS was moving away from basic research and making more optical products. We needed to team them with a business-oriented part of the corporation.

"The Strategic Defense Program Office brings multiple systems together. It seemed a natural fit," Sigman said. "Our emphasis in this new division is to change UTOS's focus from basic research to applied technology. In this business, you must have high technology. It has always been the discriminator and it always will be."

Dr. James Pearson will remain general manager of UTOS and become vice president of Strategic Defense Systems, reporting to Sigman. Sigman said he is not planning to cut any employes or restructure the management of the two operations.

Sigman said his sales target growth is 25 percent per year, starting from a $50 million base this year. "Right now there is nothing that stands in our way of that growth rate. We are in a niche market without too many competitors," he said. "When the administration shifts in 1988, the government may change its emphasis on defense. But the United States will still have a need for a strong defense."

Dominion Bankshares Corp. has affiliated with Greene County Bancshares Inc., its first bank in east Tennessee, after nine previous bank affiliations in central Tennessee. Under the arrangement, Dominion will issue 10.43 shares of common stock for each share of GCB common stock. Based on a price of $21.50 per share for Dominion, total value of the transaction is estimated to be $44.2 million.

Greene County Bancshares is the holding company for Greene County Bank, which operates seven offices in Greene County, Tenn. The bank reported of $185.4 million this year.

Dominion Bankshares owns Dominion Bank, which has eight offices in Bristol, Tenn., about 40 miles north of Greene County. Greene County Bank will be included in the same regional district.

Greene County Bank will continue to operate with its present management under the general policies of Dominion. Greene County Bank will change its name to Dominion Bank of East Tennessee in 1989.

Vitro Corp. has won a $14 million, three-year contract with the Navy's Space and Naval Warfare Systems Command.

The company will help the Navy's Warfare System Architecture and Engineering program design and coordinate weapon systems "that will be capable of functioning as a single fighting entity," said Barry Campbell, Vitro's vice president of systems integration.

Hughes Communications Inc., representing Japan Communications Satellite Co., has signed a contract to launch a satellite on a Martin Marietta Commercial Titan launch vehicle. This is the second organization to contract for satellite launch on the Commercial Titan.

The JCSAT2, a high-powered satellite, is scheduled to be launched into low-earth orbit from the Cape Canaveral Air Force Station in Florida in the summer of 1989. JCSAT is a joint venture of C. Itoh & Co., Mitsui & Co., both of Japan, and Hughes Communications, a unit of General Motors Hughes Electronics.

ICF Inc. of the District is investing up to $3 million over the next two to three years in Bios Corp., a year-old biotechnology company in New Haven, Conn. By 1990, ICF will own 48 percent of the company.

Bios is developing a series of products for molecular geneticists, including prepackaged genetic material and the instruments needed to handle the material.

The company's most important product is a large repository of DNA and ready-made DNA blots from individuals and families, with full medical and demographic histories, company officials said. The blots provide a standardized set of DNA for scientists around the country, according to a Bios official.

James O. Edwards, chief executive and chairman of ICF, will become a member of the Bios board, as will Dr. Robert J. Rubin, senior vice president and director of ICF's health and regulatory programs, and Paul Weeks II, ICF's general counsel.

BDM Corp., a subsidiary of BDM International Inc. of McLean, has been awarded a five-year contract by the U.S. Army Strategic Defense Command's (USASDC) Theater Missile Defense mission. The $108 million contract is the largest award in the company's history.

BDM will help plan systems that could provide defense against a short-range ballistic missile threat in Europe and other areas, company officials said.

The contract work will be performed in Huntsville, Ala., by a team led by BDM. The team also includes CAS Inc., Nichols Research Corp., Coleman Research Corp., Phase IV Systems Inc., Atlantic Systems Research and Engineering and several other firms.

Jiffy Lube International Inc. is in the process of reorganizing its administrative structure.

Jiffy Lube, based in Baltimore, operates a chain of more than 680 oil-change service centers in the United States, Canada and France. Under the restructuring, Jiffy Lube International will operate as a holding company with semiautonomous operating groups, each headed by a corporate executive.

The holding company will be headed by W.J. Hindman, chairman and chief executive officer. The operating groups include North American Operations East, North American Operations Midwest and West, and International Operations.

J. Richard Breen has resigned as president of Jiffy Lube International. He plans to continue with the company as a franchisee.

Oxford Development Corp., a residential and commercial developer in Bethesda, has formed the Oxford Realty Advisers Corp.

ORAC is a subsidiary of Oxford Mortgage & Investments Corp., the mortgage and investment banking arm of Oxford. The new company will encourage pension plans and similar tax-exempt plans to invest more money in multifamily housing.

"With U.S. pension assets topping the $1.7 trillion mark, Oxford is increasingly turning to this source of capital for financing both development and acquisition properties," said Don Bordman, president of Oxford Mortgage & Investments.

ORAC is a registered investment adviser under the Investment Advisers Act of 1940.

ORI/Calculon Corp., a subsidiary of Atlantic Research Corp., has won a $3.6 million contract with the Development Center Marine Corps Development and Education Command.

Calculon's engineering services will help MCDEC figure out the life cycle requirements of equipment. The company will analyze the needs of ground and air combat systems for the Marines.

Calculon has hired Markon Inc., a Marine Corps think tank in Springfield, as a subcontractor. Calculon is opening a new office in Dumfries to complete the contract work.

Engineering Resources Inc. (ERI), a subsidiary of Questech Inc. in McLean, was awarded a $2 million contract by the Naval Regional Contracting Center for the United States Naval Sea Support Center/Pacific.

Naval Sea Systems Command installs and operates shipboard equipment for the Navy's Pacific fleet. Under the contract, ERI will provide engineering and documentation services for the Navy's submarine combat systems and service schools in the Pacific.