CBS is in negotiations with David Letterman and Craig Ferguson to renew its latenight combo.

Letterman’s Worldwide Pants banner produces and owns both “The Late Show With David Letterman” and “The Late Late Show With Craig Ferguson.”

Letterman’s deal is believed to expire in late August. Sources close to the situation said Letterman’s new pact is essentially done in principal for and will take the host through 2014 — some 21 years after he joined the Eye in 1993.

“As would be expected at this time, we’re having conversations with both Dave and Craig about future years,” CBS said in a statement Thursday.

Letterman’s decision to renew is not a surprise, as his yakker is enjoying its most competitive showing in years against NBC’s “The Tonight Show.”

The status of Ferguson’s deal is unclear, but sources indicated that CBS expects him to sign up for another hitch. The longer-term question looming for Ferguson and CBS is whether he will be assured of inheriting the “Late Show” helm once Letterman decides to sign off. That issue may be a negotiating point for Ferguson’s camp in this round of contract talks.

A rep for Worldwide Pants declined comment.