Los Angeles, Aug 8 (IANS): Hollywood actor George Clooney was one of David Letterman's last guests in the final days of his tenure on CBS' “Late Show”, and now he will be among the first celebrities to grace the program under its new host, Stephen Colbert.

Colbert on Friday morning revealed via micro-blogging website Twitter Clooney would be “my first-ever guest” when the new version of “Late Show” debuts on CBS September 8, reports variety.com.

Colbert's announcement came a day after one of his biggest supporters, Jon Stewart, made his last appearance on Comedy Central's “The Daily Show.”

Colbert appeared on that program Thursday night, offering a few minutes of effusive praise for Stewart.

Clooney will give Colbert some celebrity power as he faces a tough crew of competitors.

Viewers will be watching to see how Colbert, best known for playing a bloviating character on “The Colbert Report,” will fare as himself against NBC's Jimmy Fallon and ABC's Jimmy Kimmel.