Networks $core hit

In another sign that the ad market is rebounding, the networks are selling more commercial time at higher rates than they did a year ago during the annual sales season known as the “upfront.”

CBS became the third network — joining FOX and the CW — to wrap up ad sales for the new fall TV season after securing price hikes in the “high single digits,” according to network and ad executives.

CBS’s overall upfront haul is also up in the high teens compared to last year, when the networks held back inventory in hopes of selling it later in the year when the market had recovered.

Fox, which was the first network to wrap up its ad sales on Friday, also locked in ad rate increases in the high single digits, according to ad buyers. The network, which is the leader among younger viewers ages 18 to 49, sells less ad inventory in the upfront market because it has one less hour to program during primetime.

News Corp. owns Fox and The Post.