NBC will keep Jay Leno five nights a week, but in prime time, competing not with David Letterman, but with shows like “CSI: Miami.”

The network will announce Tuesday that Mr. Leno’s new show will appear at 10 o’clock each weeknight in a format similar to “The Tonight Show,” which he has hosted since 1992.

Five years ago NBC announced that it would hand the job of host of that franchise show to Conan O’Brien in May 2009. Since then the network has maneuvered to try to keep Mr. Leno, who continues to be the late-night ratings leader, fearing that he could leave and start a new late-night show on a competitor’s network. “The Tonight Show” is seen at 11:35 weeknights.

Mr. Leno, 58, was known to have suitors, including ABC, the Fox network and the Sony television studio. But he was apparently persuaded to stay at NBC after aggressive personal wooing by Jeff Zucker, the chief executive of NBC Universal, a unit of General Electric.