Tirunesh Dibaba

of Ethiopia broke the women's world 5,000-meter record with a time of 14 minutes, 11.15 seconds at the Bislett Games yesterday in Oslo, Norway.

Dibaba, an Olympic medalist and world champion, improved by more than five seconds the previous record of 14:16.63, set by countrywoman

Meseret Defar

last year.

Justin Gatlin

's appeal to the Court of Arbitration for Sport on doping charges was unanimously rejected yesterday, three weeks before the United States holds its track trials. The CAS upheld the four-year ban given to the 26-year-old sprinter earlier this year by another arbitration panel.

The ruling ended his chances of defending his 100-meter Olympic title in Beijing.

Elsewhere.

Michael Phelps

swam the world's fastest 100-meter butterfly of the year last night. He finished in 51.04 seconds at the Mutual of Omaha Swimvitational in Nebraska.

. . .

Natalie Coughlin

won the 200-meter individual medley in American-record time at the Janet Evans Invitational, a tuneup meet in Los Angeles for the U.S. Olympic trials later this month. She touched in 2 minutes, 9.77 seconds, lowering the mark of 2:10.05 set by

Katie Hoff

.

Pro football

Dwight White

, the Steel Curtain defensive end known as "Mad Dog" who helped lead the Pittsburgh Steelers to four Super Bowl titles in the 1970s, died yesterday at age 58 in a Pittsburgh hospital.

The cause was not disclosed.

First-round pick

Darren McFadden

, the Heisman Trophy runner-up out of Arkansas, and the Oakland Raiders agreed to a $60 million, six-year contract.

McFadden, the fourth overall pick, ran for 4,590 yards and 41 touchdowns in three seasons with the Razorbacks.

Denver center

Tom Nalen

had arthroscopic surgery on his left knee, and the Broncos expect him to be ready for training camp in July.

Pro basketball

Concerned that a second tenure as the Chicago Bulls coach would spoil their friendship, former 76er

Doug Collins

told chairman

Jerry Reinsdorf

yesterday to look elsewhere for the hire.

Colleges

North Carolina point guard

Ty Lawson

was charged with driving after consuming alcohol following an early morning traffic stop in Chapel Hill.

Scout.com reported that defensive tackle

Jordan Hill

from Steelton, Pa., has chosen Rutgers over Pittsburgh, giving an oral comittment.

Unbeaten Washington and Wisconsin had narrow wins in the semifinals of the Intercollegiate Rowing Association National Championships on the Cooper River in Camden.

BYU freshman heptathlete

Chelsi Petersen

was killed in a car crash early yesterday in Provo Canyon, Utah.

Noteworthy

Scott Dixon

won the pole with

Helio Castroneves

taking second for tonight's Indy Racing League's Bombardier Learjet 550 at Texas Speedway in Fort Worth.

Ron Hornaday Jr.

held off

Kyle Busch

for the final two laps of the Craftsman Truck Series after a green-white-checkered finish for his 35th career victory, his first at Texas Speedway in Fort Worth.

Unbeaten welterweight

Floyd Mayweather Jr.

, 31, announced his retirement again, with boxing's unofficial pound-for-pound king saying he no longer has the passion

necessary to fight.