It looks like Bob Costas is ready to call it a career at NBC Sports. 

Sources say that after nearly 40 years as the network's most-prominent sports broadcaster, Costas is looking to get out of his contract early and leave the Peacock. 

His contract runs through 2021, but the longtime sportscaster has been all but invisible on the network, his most notable absence from last season's Super Bowl. 

NBC declined to comment about the negotiations. Costas couldn't immediately be reached but told the New York Post he was interested in doing a show that would take a critical look at sports and other topics.

"Sometimes you get to a point where it is not a fit anymore," Costas said. "It doesn't mean that anyone is angry or upset."