Sanford Ungar, cohost of National Public Radio's "All Things Considered," will be replaced in September by Noah Adams, according to Barbara Cohen, NPR vice president for news and information programming. Beginning in January, Ungar will host his own daily 30-minute news analysis program. It will precede "All Things Considered," the popular news and views show, Cohen said.

In addition, cohost Susan Stamberg, who has been with the program for 10 of its 11 years, has requested a four-day work week, which NPR is considering, Cohen said.

"You catch us a little before we were ready to announce this," Cohen said about the changes. "Beginning in January, we are expanding NPR's programming as part of a plan called "NPR Plus." It will be a second tier of programming available to member stations."

Cohen said "NPR Plus" will be a 24-hour service, increasing NPR's classical, jazz, and news and information programming. Hourly newscasts are also planned.

"Two and a half years on "All Things Considered" is like five years in normal life -- it's very intense," said Ungar. "Susan and I have worked really well together. I'm really delighted about the prospect of doing my own show -- I'll be able to explore single topics and the show will be on early enough that we hope people will "commit news' on the air." Ungar said that after he leaves "All Things Considered" next months, he will continue to host NPR's "Communique" weekly and will finish a book on American-African relations.

Adams, who beings as "All Things Considered" cohost in mid-September, has been host of the show's weekend edition and temporarily replaced Stamberg when she took a year's leave to write "Every Night at Five."

Stamberg is on vacation and could not be reached for comment.