Garrison Keillor says he's retiring. Once again. This time, he's set a date. Sort of.

Spring 2013 is when he'll apparently step away as host of radio's hugely successful "A Prairie Home Companion," which started in 1974 and now has 4 million listeners on 590 stations. At least, that's what he told the AARP Bulletin, a newsletter of the organization formerly known as the American Association of Retired Persons. The interview, published Wednesday, was to promote his new book, "Good Poems, American Places." But, somehow, the retirement question came up.

"When I was younger, I was all in favor of [stepping out of the limelight], and now that I'm at that age, I'm not sure," Keillor, 68, told AARP. "I sure don't want to make a fool of myself and be singing romantic duets with 25-year-old women when I'm 75. But on the other hand, it's so much fun. And in radio, the lighting is right."

Minnesota Public Radio President Bill Kling, who has known Keillor for 44 years, took his latest pronouncement about as seriously as Charlie Sheen's.

Moreover, Keillor left a loophole -- he must find a suitable replacement as host.

"I never get particularly excited about these quotes. This is the fourth time he's made reference to this over four years,'' Kling said "His view of retirement isn't the same as anyone else's. It means he'll stand in the wings, produce, write and sing and someone else will announce. If he's lucky, he'll find someone to play with.''

Three years of retirement talk

Keillor could not be reached for comment Wednesday, but it isn't the first time he has raised the retirement issue. In September 2009, in an interview with the Star Tribune shortly after he suffered a minor stroke, the radio host mentioned retiring from the show: "I'm not counting on doing it more than a couple more years."

He addressed the issue again in a Star Tribune interview in January 2010 ("I'm going to change my life in a year or two") and 12 months later when singer/fiddler Sara Watkins pinch-hit as "PHC" host for one night, with Keillor still delivering his weekly "News From Lake Wobegon" and participating in a couple of comedy sketches.

"I haven't set a date," he said then. "I've told my colleagues on the show and people at American Public Media [the show's distributor] that I really want the show to continue. But everybody comes to the end probably sooner than you think you're going to. I have no interest in trying to outlast myself. I'll be 70 in 2012. I'm not sure that a person ought to be doing this much beyond 70, to be perfectly frank."

He said he has "PHC" commitments through at least summer 2012, including a cruise from Boston to Montreal and Nova Scotia this July and out-of-town 2011-2012 "PHC" shows, where fans obviously pay to see him, and not a substitute.

Truth be told, Keillor actually quit "PHC" in 1987, moved to Denmark and then New York, where he launched a different weekly program, "American Radio Company." He revived the "Prairie Home" show in 1993 in St. Paul.

Keillor brought up the R word in November 2006, in his then-syndicated (and often political) column. After waxing about his own "End of the Trail" as well as that of the lame-duck White House occupant, he ended with: "Retirement is recommended. The sooner the better." Of course, it wasn't clear if he was talking about himself or about then-President George W. Bush. But then, Keillor is often confusing when he talks about retirement.

Staff writer Neal Justin contributed to this report. Jon Bream 612-673-1719 twitter @jonbream