Eddie Lopat, one of the three pitching mainstays for the New York Yankees during their reign of five straight World Series championships from 1949 to 1953, died in his sleep early yesterday at the home of his son, John, in Darien, Conn. He was 73 years old.

Mr. Lopat, who lived in Hillsdale, N.J., had been battling a recurrence of pancreatic cancer, his son said.

In 12 seasons in the major leagues, four with the Chicago White Sox, seven with the Yankees and one split between the Yankees and Baltimore Orioles, the left-hander won 166 games, lost 112 and compiled an earned run average of 3.21.

He combined with a pair of right-handers, Allie Reynolds and Vic Raschi, to form the heart of the pitching corps that carried Casey Stengel's Yankees to five straight titles, three against the Brooklyn Dodgers.

But while Reynolds and Raschi relied on fast balls and curveballs, Steady Eddie Lopat used an assortment of pitches he threw at different speeds with the same motion, earning the nickname The Junk Man.

After his release by Baltimore, Mr. Lopat served as manager of the Yankees' farm club in Richmond of the International League. He managed the Kansas City Athletics in 1963 and 1964.

He won 113 games and lost 59 with the Yankees, his best year being his 21-9 record in 1951, his only season as a 20-game winner. He had a 4-1 record in five World Series, including 3-1 and 13-1 complete-game victories over the New York Giants in their "miracle" year of 1951.

Edmund Walter Lopatynaski was born in New York City, grew up playing stickball on the Upper East Side of Manhattan and was graduated from DeWitt Clinton High School in the Bronx. Originally signed by the Dodgers, he spent seven years in the minors before being brought to the majors by the White Sox in 1944. He was traded to the Yankees in February 1948 for Aaron Robinson, Fred Bradley and Bill Wight, none of whom ever achieved anything close to Mr. Lopat's fame.

In describing his pitching, the former manager Paul Richards once said: "Lopat throws his slow ball with the identical motion he throws his fastball, slider, screwball or any other pitch. Each looks the same as it leaves his hand, but it's the different speeds which keep the batter off balance."

The sports columnist Red Smith once said that Lopat's pitches "never exceeded the speed limit," and Lopat once explained how he was successful with Ted Williams of the Red Sox, the best hitter at the time:

"I never threw the same pitch twice and never to the same spot twice and he didn't like it."

Besides his son, Mr. Lopat is survived by his wife, Elizabeth; a daughter, Melissa, of West Palm Beach, Fla.; a brother Ted, of Tacoma, Wash., two sisters, Stephanie and Sophie, both of Tucson, and a grandson, Christopher, of Darien.

Edmund Lopat