Emanuel Fthenakis in 1981. (Gerald Martineau/TWP)

Emanuel Fthenakis, who helped develop early satellite communication systems for military and commercial use and steered the Northern Virginia-based defense electronics firm Fairchild Industries through a takeover in the late 1980s, died April 3 at a hospital in Rockville, Md. He was 86.

The cause was complications from a gastric perforation, said a son, Basil Fthenakis. He was a resident of Potomac, Md.

The Greek-born Mr. Fthenakis (pronounced tha-NAKUS) trained in electrical engineering at Columbia University and began his professional career on the technical staff at Bell Laboratories in New Jersey. He later helped lead General Electric Co. and Ford Motor Co. into the satellite and aerospace business.

In the early 1970s, Mr. Fthenakis started American Satellite Co., a Rockville-based company that specialized in transmissions of large amounts of data via satellite technology. Among its hundreds of private and government clients were Bank of America and the Wall Street Journal.

American Satellite became a subsidiary of Fairchild Industries, where Mr. Fthenakis rose through executive ranks to become chairman and chief executive by the mid-1980s. He was credited with accelerating a plan to restructure Fairchild — then based in Chantilly, Va. — amid strong declines in defense spending and greatly reduced demand for commercial aircraft manufacturing. The focus was instead placed on Fairchild’s aerospace as well as electronic components for industrial use.

Mr. Fthenakis helped guide Fairchild Industries through its acquisition by Banner Industries, a Cleveland-based aerospace parts company. The deal was valued at about $400 million, including $136 million in assumed debt.

After the completion of the sale in 1989, Mr. Fthenakis stayed on two more years and retired. He was succeeded by Jeffrey J. Steiner, the takeover specialist who had been chief executive of Banner.

The company, which became known as the Fairchild Corp., added motorcycle protective apparel to its offerings, operated at a loss for years and went into severe decline after Steiner’s death in 2008.

Emanuel Fthenakis, who later took the middle name John after his father’s first name, was born in Thessaloniki, Greece, on Jan. 30, 1928. He participated in the Greek resistance during World War II, his family said.

After graduating in 1951 from the National Technical University of Athens, he received a master’s degree in electrical engineering from Columbia in 1954. He became a U.S. citizen a few years later.

His first marriage, to Polixeni Makarounis, ended in divorce. Survivors include his wife of 41 years, Hermione Coates Fthenakis of Potomac; two sons from his first marriage, John Fthenakis of Medford, Ore., and Basil Fthenakis of Mountain View, Calif.; and four grandchildren.

While at Fairchild, Mr. Fthenakis was appointed by President Ronald Reagan to the National Security Telecommunications Advisory Council and was an adjunct professor at the University of Maryland, where he taught a graduate course in space and communications technology. He sat on many boards, including the scientific research consortium University Research Association.