Jeremy Levin, an American journalist kidnaped here last March by Moslem militants, appeared early this morning near a Syrian Army post near Baalbek in Lebanon's Bekaa Valley. He was taken in Syrian custody to Damascus, and U.S. officials said he was well and would be turned over to the U.S. Embassy there.

Levin, 51, the Beirut bureau chief of Cable News Network, told Agence France-Presse in Damascus that he had escaped Wednesday night from a villa in central Lebanon where he was being held and walked to his freedom. One of five Americans kidnaped here in the past year, Levin reportedly said he had been held alone by his captors and knew nothing about the others.

The development took U.S. officials by surprise, according to State Department sources. There were indications of Syrian involvement in negotiations, however, and many private U.S. citizens, including the Rev. Jesse Jackson and Muhammad Ali, had pressed publicly for his release. Arrangements were being made to fly Levin and his wife, Lucille, to a reunion in Europe. Details on Page A18.

An anonymous caller claiming to speak for the Islamic Jihad organization told a western news agency here today that the group had freed Levin after determining that he was not a spy.

Islamic Jihad, a shadowy organization with no visible structure but believed to be associated with Shiite Moslem fundamentalists here, had claimed responsibility for the kidnaping of Levin as well as the other four Americans who disappeared in the past year in west Beirut, which fell into the hands of Moslem militia groups on Feb. 6, 1984.

Levin was last seen on March 7, when his wife left their home as he was preparing to go to work. He never reached his office.

According to the Bekaa Valley correspondent of AFP, Levin said today that on the day of his disappearance he had been walking near the coast in west Beirut when he was accosted by a bearded man in his twenties who pushed him at gunpoint into a car and took him to his place of detention.

AFP quoted Levin as saying he had been kept alone in a room, tied to a radiator. He said his jailers blindfolded him every time he was taken out of the room. He said he could not identify his abductors.

Levin said had remained in the Bekaa Valley throughout his captivity, but that his place of detention had been changed four times.

"I escaped Wednesday at around midnight from a two-story villa where I was being held," he told AFP. "I walked for two hours in the Bekaa plain before hearing dogs barking and human voices. Thinking my assailants were following my tracks, I hid under a truck. However, as soon as I saw that they were Syrian soldiers, I turned myself over to them."

It was 2 a.m. local time, AFP reported, when a bearded and pajama-clad Levin approached the Syrian soldiers, who took him to Syrian military police nearby. AFP said he seemed to be in good health but fatigued by his detention and long trek.

The police took him to a Syrian Army intelligence post in Baalbek, 55 miles northeast of Beirut.

Syrian troops control most of the Bekaa and parts of northern Lebanon. The report of Levin's escape is similar to that of Reuter correspondent Jonathan Wright, who was kidnaped in the Bekaa last fall and escaped 21 days later.

Wright said he was certain he had escaped on his own. But there were reports that intensive efforts with go-betweens in touch with groups based in central Lebanon as well as a plea by Syrian President Hafez Assad to forces in the area to help in the search were instrumental in gaining his release.

While little is known about Islamic Jihad, Lebanese officials say it could be a front for a group seeking to destabilize Lebanon. It claimed responsibility for the suicide bombings against the U.S. Embassy in west Beirut in 1983 and outside east Beirut last year as well as for the attacks against U.S. and French military barracks in October 1983.

On Jan. 11, a telephone caller told The Associated Press here that the Americans would be released if all U.S. citizens left Beirut. On Jan. 14, a caller claiming to speak for Islamic Jihad said it would try the Americans it was holding as spies.

The Americans still missing are William Buckley, a political officer at the U.S. Embassy who was kidnaped March 16; the Rev. Benjamin Weir, a Presbyterian minister kidnaped May 8; Peter Kilburn, a librarian at the American University of Beirut, reported missing Dec. 3; and the Rev. Lawrence Jenco, director here for the Catholic Relief Services, who was kidnaped Jan. 8.

The caller today who claimed to be from Islamic Jihad, speaking in Arabic, said: "We released . . . Levin after many approaches by some brotherly and effective sides . . . after our investigations established he was not involved in espionage or subversion against Islamic forces."

The reference to approaches by "brotherly and effective sides" suggested that pressure may have been exerted by Syria, the only quarter that has any authority in central Lebanon.

The caller added: "We are asking the president of the American University of Beirut and some Lebanese and foreign professors not to interfere in Lebanese political affairs and not to adopt an attitude hostile to Moslem causes. Otherwise their fate will be like that of their predecessors."

Malcom Kerr, then president of the university, was shot and killed outside his office on Jan. 18, 1984.

The caller said the warning was prompted by the group's noting some suspicious activity by some members of the university's administrative and educational staff recently. He gave no details.