NEW YORK (AP) _ Joe Garagiola, the avuncular ex-baseball player hired as a ''Today'' co- anchor 20 months ago when NBC was trying to halt its ratings slide, is stepping down from that role, NBC said Thursday.

But his current contract has been extended and he will stay with the show on which he first was a co-anchor from 1969 to 1973, NBC said.

Starting Monday, Garagiola, 65, will work as a special correspondent specializing in sports and human interest stories. He will be based in Phoenix, where he lives.

NBC said the move was made at his request.

''He wanted to spend more time in Arizona,'' said ''Today'' spokeswoman Lynn Appelbaum.

Garagiola left NBC Sports in 1988 after 27 years, and was doing play-by- play coverage of California Angels home baseball games for cable TV's SportsChannel when he agreed to return to ''Today'' on a three-day-a-week basis.

His comeback in June 1990 was part of NBC's effort to revamp the show, whose ratings had slumped following the controversial replacement of 13-year veteran Jane Pauley with Deborah Norville.

The show's ratings continued to slide, and Norville left ''Today'' and NBC last year. She was succeeded by Katie Couric, who joined Garagiola and Byrant Gumbel as co-anchors.

The show's Nielsens have slowly returned. Two weeks ago ''Today'' broke the 109-week winning streak of ABC's ''Good Morning America'' by a narrow margin. Last week's national morning-show ratings are't due until Friday.