A Navy enlisted intelligence specialist and aspiring spy novelist has been sentenced to six years' hard labor for what prosecutors said was an abortive effort to get Soviet officials to pay him between $1,000 and $3,000 for U.S. military secrets.

A spokesman for Atlantic Fleet headquarters said Brian P. Horton, 28, of Cos Cob, Conn., was court-martialed in Norfolk for offering the Soviet Embassy classified information, including access to SIOP--"the Single Integrated Operation Plan, the general war plans of the United States."

The SIOP is a classified, detailed master plan of how the United States would fight a war, complete with details of what forces would be deployed under various circumstances.

Horton, a second-class petty officer with top-secret clearance, was an analyst in the nuclear-strike planning branch of the Navy's sensitive Fleet Intelligence Center. His contacts consisted of four telephone calls to Washington and a letter from Horton to the embassy between April and October last year, the spokesman said.

Authorities said details about how the contacts were traced during a six-month investigation by naval security officials and the FBI were classified. No secret information was furnished to the embassy by Horton and no money changed hands, according to the spokesman.

Horton pleaded guilty during a three-day court-martial this week to five counts of failing to report his contacts with the Soviet officials, a violation of military law. He was convicted by a military judge of a sixth count of soliciting money for Navy secrets. Horton faced up to 11 years' imprisonment in the case.

The Navy said yesterday that prosecution testimony indicated Horton, whose year-old son and pregnant wife live in the Norfolk area, was motivated by a need for money, but the sailor's civilian lawyer disputed that contention.

"He was working on a number of manuscripts for a novel or novels -- spy thrillers. That was and is our contention," said attorney Robert B. Armstrong of Huntington, N.Y. Armstrong said Horton approached the Soviets "to learn their M.O. method of operation -- how they would handle something like this."

Horton described his own conduct as "asinine. In retrospect he realized that what he had done was an entirely foolhardy thing," Armstrong told the Associated Press.

Horton wanted the information for use in his writing, including a proposed novel to be called "Operation Heartbreak" with a "double-agent concept," according to Armstrong.

The lawyer said various manuscripts and handwritten notes for "Operation Heartbreak" were submitted as evidence at the court-martial, portions of which were closed to the public for security reasons.

Armstrong said that although the government attempted to show Horton was suffering financial problems and had discussed bankruptcy at one point after reporting for duty in Norfolk last April, he had received a reenlistment bonus of more than $10,000 from the Navy early last year.

"On and off the job he was very much involved in espionage and intelligence concepts," said Armstrong. He said Horton's father, an employe of Western Electric in Connecticut, testified his son was devoted to war games as a youngster. "Something called 'War in the Pacific' was always spread out on the living-room floor," Armstrong quoted the father as testifying.

"He was into war gaming -- plotting and planning," Armstrong added.

Horton's parents were "extremely upset" by the outcome of the court-martial, the lawyer said. Horton, described as "a 4.0 sailor" by one officer, also was reduced to the lowest enlisted grade, deprived of all pay and allowances and will be dishonorably discharged as part of his sentence.

Horton, who is being held at the Norfolk Naval Station brig, acknowledged writing the letter and sending it to the Soviet Embassy. The letter was never recovered, his lawyer said.

The Navy spokesman, Lt. Cmdr. Dale Smith, said Horton was assigned to an intelligence section dealing with Europe and the Atlantic, but declined to furnish further details of the sailor's job. The Fleet Intelligence Center is under the joint control of the Atlantic Fleet's commander-in-chief and the Navy's European command.

Horton enlisted in the Navy in August 1979 and received basic training in Orlando, Fla. He was stationed aboard the aircraft carrier Enterprise in Japan before reporting for duty in Norfolk April 20. He was promoted to third class petty officer in February 1981 and promoted again to second class last March.

His conviction will receive automatic review by a Navy-Marine Court of Review. Armstrong said yesterday he expected the case to be appealed to the U.S. Military Court of Appeals.