HBO’s Ross Greenburg is leaving the network after nearly eleven years as president of the sports division. Greenburg will resign from HBO Sports on Monday after electing not to renew his contract with the network, according to multiple reports. Greenburg had been with HBO since 1978. Sports By Brooks reported Sunday that Greenburg was fired from HBO, in part for losing the Manny Pacquiao/Shane Mosley bout to rival Showtime, but he denied those allegations to Yahoo! Sports and the New York Times. Instead, he described his departure as being months in the making, the result of increasing disillusionment with the business of boxing negotiations, according to SMW.