Rob Feder is speculating this morning that the Tribune’s WGN-AM, the top-rated news/talk station in city and a Chicago institution, may be on the auction block.

As reported here, there’s been a lot of talk in recent weeks about media cross-ownership, and the Tribune has been in the center of the bullseye, with its portfolio of print and broadcast properties.

Feder claims that FCC Chair Kevin Martin would like to see WGN-AM spun-off as a condition of the Tribune’s sale to Sam Zell:

The prospect of top-rated news/talk WGN-AM (720) going on the block moved a step closer to reality this week with news that FCC chief Kevin Martin has proposed the sale as a condition of allowing Tribune Co. to own both WGN-Channel 9 and its newspaper here under Sam Zell.

However, the only comments we can find from Chairman Martin seem to indicate a disposition towards allowing the Tribune to keep the newspaper, the TV station, and the radio station:

“I would certainly be sympathetic to the original grandfathers,” he said. “I think the right answer would be to maintain the original grandfathers that were in place in 1975.”

The official FCC release of Martin’s remarks can be read here.

Feder speculates that a prime candidate to purchase WGN-AM if it were to go up for sale would be Bonneville International, who already own radio stations in Chicago.