WASHINGTON - Jim McKay, the sportscaster who brought the "thrill of victory and the agony of defeat" into U.S. homes as the longtime host of ABC's Wide World of Sports and who anchored the network's coverage of the terrorist killings of 11 Israeli athletes at the 1972 Summer Olympics, died Saturday at his farm in Monkton, Md.

The Philadelphia native was 86. The cause of death was not disclosed.

Mr. McKay was a versatile sportscaster who exerted a quiet but powerful influence on his craft for more than 40 years. As the host of Wide World of Sports, he helped popularize dozens of sports, from figure skating to ski jumping to Mexican cliff diving, that had previously been followed by only a small cadre of fans.

His specialty of describing the human pathos that transcended a contest's results helped him become the first sportscaster in television history to win an Emmy Award.

Mr. McKay gained his greatest renown, though, for his sensitive coverage of 12 Olympiads, most notably the 1972 Summer Games in Munich. When Arab terrorists seized Israeli hostages at Munich's Olympic Village, ABC Chairman Roone Arledge chose him to anchor the network's broadcasts, rather than regular host Chris Schenkel or the better-known Howard Cosell.

Mr. McKay's calm, dignified presence propelled him from the simplicity of sports to the complexities of international politics and terror. He stayed on the air for 16 hours, his unshaven beard growing thicker, as he explained to the world how sports had suddenly lost its innocence.

"It was on that tragic day, Sept. 5, 1972," William Taaffe wrote in Sports Illustrated in 1984, "that he became the very image and voice of the Games - Mr. Olympics."

Mr. McKay described the scene with a plain-spoken eloquence that captured the gravity of the moment. With the ABC broadcast center only 100 yards from the Olympic Village, there was fear that the terrorists might try to storm the building and take ABC employees, including Mr. McKay, hostage.

When the end of the siege came, he described it to a shocked world: "When I was a kid, my father used to say our greatest hopes and our worst fears are seldom realized," he said. "Our worst fears have been realized tonight. They have now said that there were 11 hostages. Two were killed in their rooms this - excuse me, yesterday - morning. Nine were killed at the airport tonight. They're all gone."

Mr. McKay won two Emmy Awards for his coverage of the crisis, one for sports and one for news - the only time a sports reporter has received an Emmy in news.

"He brought a reporter's eye, a literate touch, and above all a personal humanity to every assignment," broadcaster Bob Costas said. "He had a combination of qualities seldom seen in the history of the medium, not just sports."

James Kenneth McManus - Mr. McKay's legal name throughout his life - was born Sept. 24, 1921, in Philadelphia. Growing up a Philadelphia Athletics fan, he attended Our Lady of Lourdes School in Overbrook and then St. Joseph's Prep before he moved with his family to Baltimore when he was 14.

He was a 1943 graduate of Loyola College. After commanding a Navy minesweeper during World War II, he returned to Baltimore and found a job as a reporter with the Evening Sun.

When the paper began a television station in 1947, McManus (as he was then known) was given a daily sports show and became the first host of a broadcast produced in Baltimore.

In 1950, he moved to New York and WCBS-TV. When an executive decided to name his show The Real McKay, James McManus became forever known as Jim McKay. He did a variety of television work, including the Masters golf tournament and the 1960 Olympics in Rome for CBS.

When ABC's Arledge devised Wide World of Sports, he turned to Mr. McKay. The show premiered April 29, 1961, and Mr. McKay remained its host for more than 25 years, intoning the famous lines that opened each week's edition: "Spanning the globe to bring you the constant variety of sports . . . the thrill of victory and the agony of defeat . . . the human drama of athletic competition."

Mr. McKay also covered major golf tournaments and horse races - his two favorite sports - and was a fixture of ABC's Olympic coverage through 1988.

His son, Sean McManus, is president of CBS News and Sports. In addition to his wife and son, Mr. McKay is survived by a daughter, Mary Guba of Sparks, Md., and three grandchildren.