CLEVELAND — Jim Donovan, the Cleveland Browns’ popular radio play-by-play announcer and a staple in televised sports for more than four decades, died Saturday. He was 68.

Donovan retired from his broadcasting career earlier this year and stepped down from his game day duties with the team before this season while battling cancer. He had called Cleveland’s games since the team’s rebirth in 1999.

“This is an incredibly difficult day for us and the entire Cleveland Browns organization,” said Browns owners Dee and Jimmy Haslam. “His impact as the voice of the Browns for 25 years is immeasurable, as he has touched the lives of our fans every Sunday with his love for the Browns and his brilliance at his craft.”

“He will be greatly missed, but he has cemented a legacy that will live on forever. The only thing that outweighed his love for this city and this team was the love he had for his family. Our thoughts and prayers are with his wife, Cheryl, his daughter, Meghan, and everyone who was fortunate enough to call Jimmy family or friend.

Donovan, a Boston native known to all as “Jimmy,” endeared himself to Cleveland fans with his passion, sense of humor and professionalism. He paid great attention to detail and spent countless hours preparing the game broadcasts.

Donovan was recently inducted into the Browns’ Legends Club and the Greater Cleveland Sports Hall of Fame. He had been too ill to attend the events.

When he was forced to resign in August, Donovan wrote a letter to Browns fans thanking them for their support.

“I have been officiating Browns games for 25 years. Not a day went by that I didn’t stop and feel so proud to be ‘The Voice of the Browns,'” he wrote. “Cheryl, Meghan and I thank you for all the love, support and prayers during my difficult times. It’s like we have a huge family around us. And that’s what makes the Cleveland Browns so special. You do.”

Donovan had to step down as sports director at WKYC-TV for several months last fall to undergo treatment for leukemia. He returned to the broadcast booth in time to announce the team’s advance to the playoffs at the end of the season.

He was diagnosed with chronic lymphocytic leukemia in 2000 and underwent a bone marrow transplant in 2011.

A graduate of Boston University, Donovan came to Cleveland in 1985. In addition to local coverage of the city’s three professional sports franchises, Donovan also held several national network assignments and was part of NBC’s coverage team at the 1992 and 1996 Summer Olympics.