Developing: MSNBC is giving regular "Countdown with Keith Olbermann" fill-in host Lawrence O'Donnell the 10 p.m. hour, the network says.
O'Donnell will start developing the program immediately, though no format, title or start date has been set.
"Lawrence O'Donnell is an incredible talent, who our audience has gotten to know throughout the years, most recently as Keith Olbermann's principal guest host on 'Countdown.' It's great to have another anchor of his caliber on the network," said MSNBC president Phil Griffin in a statement. "This makes us a bigger and better network."
"I've had a part-time job at MSNBC for 14 years," said O'Donnell in a statement. "Now that the network and I have gotten to know each other, I'm thrilled to be going full time."
When O'Donnell's show starts, the 10 p.m. rerun of "Countdown" will move to 11 p.m..
The move is a surprising one, as MSNBC has said as recently as October that it was happy with how the "Countdown" repeats have bee performing at 10 p.m.
Still, both CNN and Fox News have originals at 10 p.m., so rumors of an expansion into that hour are nothing new to MSNBC.
Olbermann was out for much of March due to his father's illness and passing, with O'Donnell doing most of the fill-in duties. As we reported, that was Countdown's highest rated month that quarter.