- Amazon's bid includes the New York-based YES Network, which is partly owned by Yankee Global Enterprises.
- Apollo Global Management, KKR, Blackstone, Sinclair Broadcast and Tegna are also making first-round bids for the regional networks, sources tell CNBC.
- Fox, which was seen as a front-runner to acquire back the channels it recently sold to Disney, did not enter a first-round bid.
The e-commerce giant's bid includes the New York-based YES Network, sources familiar with the matter told CNBC. It is bidding for the New York network along with an unknown sovereign wealth fund and the Yankees, the sources said. YES may be sold separately from the other networks.
Fox, which owns the YES Network with the New York Yankees, was seen as a front-runner to bid for the nearly two dozen regional networks. They broadcast the games of 44 professional teams from Major League Baseball, the National Basketball Association and the National Hockey League.
Fox itself did not submit a bid in the first round for the networks although there's potential that it will join in the second round, the sources told CNBC. Earlier this year, Fox sold some television and movie assets to Disney, which owns the sports channel ESPN. The Justice Department forced Disney to sell the Fox regional sports networks to get that deal done.
Fox acquired its 80 percent interest in the YES Network in separate transactions in 2012 and 2014. YES is home to the New York Yankees and also carries Brooklyn Nets games.
The second round of bids is expected before year-end and due diligence on the bids begins next week. CNBC was unable to learn the amounts of the bids.