Starting with the 2013-14 season, WEEI will no longer air Celtics games, according to Boston.com's Chad Finn.
Entercom Communications runs the WEEI and WRKO stations that have carried Celtics games since 2005.
"WEEI has had an incredible run with the Boston Celtics, from being a part of their 17th championship banner to the end of the Big 3 era," said Entercom Boston vice president/market manager Jeff Brown in a statement to Boston.com.
"Unfortunately we were unable to come to terms on a new contract moving forward. We thank the entire Celtics organization for our tremendous time together and wish them the best of luck in the future."
There is no word yet as to which radio station will carry Celtics games next season.