Alex Barnes Shipley Jr., 37, who helped established that former president Richard M. Nixon's 1972 reelection campaign engaged in widespread spying and sabotage against the Democrats in addition to the Watergate bugging, died Monday at Vanderbilt University Medical Center in Nashville.

He suffered a heart attack after jogging at the First American National Bank's athletic facility in Nashville.

Mr. Shipley was a major source for an Oct. 10, 1972, Washington Post story by Carl Berstein and Bob Woodward, which described in detail the extent of the "dirty tricks" in which the Committee to ReElect the President engaged. Previous stories the concentrated on the break-in at the Democratic National Committee headquarters at the Watergate and on apparent financial irregularities in the Nixon campaign.

The Bernstein-Woodward story named Donald H. Segretti, then 31, a former attorney in the Treasury Department, as a recruiter in the sabotage efforts. It said the campaign against the Democrats inculded Seizing confidential campaign files and investigating the private lives of Democratic campaign workers.

Mr. Shipley, a Democrat, was approached in 1971 by Segretti, whom he had known in the Army, and asked to work as an "agent provocateur" against the Democrats. He refused to do so.

Bernstein and Woodward considered the discovery of the link between these political "dirty tricks" and the Nixon administration's "offensive security" to be one of the most significant developments in the Watergate story prior to Nixon's reelection in 1972. The scandal eventually forced Nixon to resign from the presidency. Several of his top aides were imprisoned.

Mr. Shipley was an assistant attorney general of Tennessee by the time these events occurred.

A native of Tennessee, Mr. Shipley graduate from the University of the South in Sewanee, Tenn., and earned a law degree from the Univeristy of Tennessee in Knoxville. He did graduate work in history at Emory University in georgia.

He served as a captain in the Army. Judge Advocate General Corps in Vietnam and Washington, where he first met Segretti.

A specialist in communications and labor law, Mr. Shipley was a partner in the Nashville law firm of King and Ballew at the time of his Death. He had been with the firm since about 1975.

He played bass fiddle in a Nashville bluegrass group called "Outbound Freight."

Survivors include his wife, Marietta Mundinger Shipley, of the home, an attorney with the Davidson County (Tenn.) district attorney's office; his parents, Dr. and Mrs. Alex b. Shipley Sr., and a brother, Will T., all of Knoxville, and a sister, Suzanne Glover, of Thousand Oaks, Calif. CAPTION: Picture, ALEX B. SHIPLEY JR.