For sale: Charter franchise of Major League Baseball located in major Midwestern city. Fixer-upper has not won World Series in 99 years. Landmark ballpark not included?

On Opening Day of the 2007 baseball season, owner Tribune Co. announced it is putting the Cubs on the block as part of its $8.2 billion sale to real estate tycoon Sam Zell. Tribune Co.'s 25 percent interest in broadcast partner Comcast SportsNet Chicago also will be sold.

But there is a catch that might elicit frowns from some potential bidders: the "Friendly Confines" of Wrigley Field might not be for sale. The Tribune press release announcing the sale made no mention of Wrigley, and company officials Monday declined to comment on whether the ballpark -- which is as much a part of Cubs lore as the team itself -- is on the market.

The Cubs could fetch "anywhere from $500 million to $600 million" from a buyer even without Wrigley, said Andrew Zimbalist, a Smith College professor who specializes in baseball economics. The Comcast stake is believed to be worth at least $50 million.

Wrigley would be expected to add as much as $90 million to the asking price. With its unique red marquee at the corner of Clark and Addison Streets and its trademark ivy-covered walls, Wrigley's value to Chicagoans goes beyond mere dollars and cents.

Yet the ballpark's landmark status limits an owner's ability to change the look of Wrigley. Tribune Co.'s efforts to expand the bleachers were delayed by intensive negotiations with the city and neighbors. Even changes outside the ballpark are prohibited by the landmark status.

With or without Wrigley Field, prospective buyers are expected to line up to purchase the Cubs. And the sale will represent a big return for Tribune, which paid only $20.5 million to buy the club in 1981.

The list of prospective buyers is expected to include well-known sports figures such as Jerry Colangelo, a Chicago Heights native who was managing partner of the Arizona Diamondbacks when they won the 2001 World Series. Also among the likely bidders is Mark Cuban, the brash technology entrepreneur who sits courtside and jaws with officials as owner of the Dallas Mavericks NBA team.

Yet Major League Baseball Commissioner Bud Selig, in a visit to U.S. Cellular Field on Monday for the White Sox opener, indicated he would prefer to find a local buyer.

"Whenever you can find viable local ownership, that's a good thing. A very good thing," Selig said. The Comcast investment "will probably get sold right along with the ballclub," Selig added.

White Sox Chairman Jerry Reinsdorf figures Selig will not have to look very far. "I know of seven different groups that are interested in buying the Cubs," Reinsdorf said.

Expect "some wild bidding," Reinsdorf added. "The Cubs are a premier franchise. They will go for a good number."

Local bidders may include Don Levin, the owner of minor-league hockey's Chicago Wolves who made an offer for the Cubs last fall. Andy McKenna, the septuagenarian Chicago civic leader who served as chairman of the Cubs early in the Tribune Co. ownership, is mentioned as capable of putting together an investor group. Chris Reyes, chief executive of privately owned Reyes Holdings, might consider a minority position in the Cubs, sources said.

The ballclub has a unique cachet, with a national reputation as "lovable losers" that current Tribune Co. management has struggled to overcome, spending $300 million over the past winter to upgrade the roster. The Cubs have not won a World Series since 1908, and last appeared in one against Detroit in 1945 . Yet they retain a loyal national following, setting attendance records in each of the last three seasons by drawing more than 3 million fans.

One such fan is Cliff Zeider, a 75-year-old resident of Port St. Lucie, Fla., who grew up watching the Cubs in LaPorte, Ind. These days, Zeider says, sometimes he thinks the Cubs "should just move to Japan. I am sick of this bunch of losers." That didn't stop Zeider from tuning in to see the Cubs lose 5-1 in Cincinnati on Opening Day.

Yet, Zeider doesn't entirely blame Tribune Co. "Tribune has nothing to do with it," he said. "They don't know enough about baseball to hurt anything."

Ownership of the Cubs has been a mixed blessing for Tribune Co. Among the newspaper's readers are many White Sox fans who believe the Chicago Tribune favors the Cubs because of its parent company's ownership. Even Mayor Daley sometimes chides the Tribune. In 2005, as the White Sox bore down on their World Series title, Daley scoffed at a Tribune story about the Black Sox scandal of 1919. "Why do they have to bring that up? Here [the Sox] are coming into a tough game tonight. They won't do it against the Cubs, I'll tell you that."

Tribune Chief Executive Dennis FitzSimons made reference to the Cubs' long drought while talking about the Zell sale to Tribune employees Monday. "We have one more chance in our 25 years of ownership," FitzSimons said. "Maybe the 25th time will be the charm."

FitzSimons in an interview Monday said he has fielded offers to buy the Cubs for years, and Tribune Co. management looked at the prospect of a Cubs' sale during the course of its months-long strategic review. The idea to sell the team as part of Zell's purchase process occurred during negotiations, FitzSimons said.