Times Mirror CEO Mark Willes is putting The Sporting News on the block – less than two years after pledging to inject $20 million to rejuvenate the 113-year-old weekly.

Efrem Zimbalist III, president of Times Mirror Magazines, said he would try to sell the magazine to a company that had a strong broadcast or cable affiliation.

“It needs someone with a much bigger electronic footprint,” Zimbalist told The Post.

“This is the only book we have that deals with spectator sports as opposed to participatory sports.”

Times Mirror Magazines publishes Field & Stream, Outdoor Life and Popular Science.

But at least one rival publishing source said a sale to a broadcaster was unlikely and that a publishing company was more probable.

Staffers of The Sporting News who got the word yesterday were stunned.

“I think the timing was a surprise,” said one. “I would have thought they would have wanted to watch it play out a little bit more, but I think it was driven by other corporate strategies.”

Industry sources said they believed the weekly was still losing several million dollars a year and had probably spent just over $5 million of the $20 million re-design budget.

The expensive overhaul of the paper didn’t do much to budge the circulation, which inched up 1.7 percent in the first half of 1999 to 549,222. The single-copy circulation tumbled 21.4 percent to 30,494.

Advertising in the first eight months of the year rose 7.1 percent to 574.7 while ad revenue rose 15 percent to $15.6 million, according to the Publishers Information Bureau.

Times Mirror rose 3 to 61.