Jeff Probst will also return

Still going fairly strong on the eve of its 16th season premiere, "Survivor" has been renewed for at least two additional installments.

And not only will "Survivor" be back on CBS for a 17th and 18th engagement, but host Jeff Probst has also signed on to return.

"It is truly a remarkable feat to be winning your time period in all ratings categories after 15 editions," says Ghen Maynard, CBS' unscripted guru. "The show's success is testimony to the creativity and passion of Mark, Jeff and the entire production team and to a brilliant concept that continually introduces new casts and settings, making each season feel like a new series."

"Survivor: Micronesia," a half-and-half all-stars/fans season, will premiere on Thursday, Feb. 7, the follow-up to "Survivor: China," which saw the reality franchise dip to 15.2 million viewers per week. That's well below what the show used to do in its prime, but comfortably ahead of anything else in its time period including more hyped scripted shows like ABC's "Ugly Betty."

"I still get excited to get on the plane and travel to another exotic location with another group of adventure-seeking, type-A personalities," Probst says. "It is without question the best job I've ever had."

Series producer Mark Burnettt adds, "I am looking forward to many more seasons of 'Survivor.' It has become an expected treat every Thursday at 8:00 p.m., and I am glad our loyal fans can continue their appointment television with us."

The two freshly ordered seasons -- No. 17 is currently casting -- will air in the fall and spring of the 2008-09 season.