The Blackhawks announced McDonough as the new team president at a news conference Tuesday.
Blackhawks chairman Rocky Wirtz said the best person to take over the team was "right in front of our nose." Wirtz said they wanted to bring someone in to coordinate hockey operations.
"The Cubs congratulate John McDonough on his new position," said Crane Kenney, Tribune Co. executive, to whom McDonough reported. "In his time as team president, John helped the club take an important step toward our ultimate goal -- bringing a championship to the greatest fans in baseball."
McDonough has been the Cubs' team president since Oct. 1, 2006, when he replaced Andy MacPhail, who resigned after a 96-loss season. At that time, McDonough boldly announced the Cubs' mission was to win the World Series.
"The purpose of why I've been asked to do this job is for the Cubs to win the World Series -- not win the Wild Card or win the division or win the pennant," McDonough said when introduced as interim president last year. "It's time to win. It's time to win the World Series."
McDonough was behind the hiring of Lou Piniella as manager, and the overhaul of the team, which included spending more than $300 million on players such as Alfonso Soriano, Ted Lilly, Jason Marquis and Mark DeRosa.
In 2007, the Cubs rebounded to win the National League Central, but they were swept by Arizona in the NL Division Series.
"The Cubs were terrific to me from top to bottom," McDonough said Tuesday. "That's a big part of my life. Being part of an organization for 24-plus years and having so much respect for everybody over there, but the opportunity that Rocky presented to me -- and this came together rather quickly -- was something I was quite impressed with."
McDonough's long-term job status with the Cubs was uncertain because of the pending sale of Tribune Co. and the likely sale of the Cubs. He signed a multiyear contract with the Blackhawks. Whoever replaces McDonough will likely be on an interim basis until the new ownership is named.
"We will not let the ownership transition distract us from our primary goal -- to see a championship come to the Chicago Cubs in 2008," Kenney said. "Tribune's commitment through an expanded payroll and additional capital for Wrigley Field evidences the continued focus on taking the next step for Cubs fans.
"Jim Hendry has a well-constructed plan in place and is already working to strengthen our roster for 2008," Kenney said. "We also have a new, multi-million-dollar playing surface ready to welcome our team on Opening Day."
McDonough met with front-office staff Tuesday at Wrigley Field to announce his resignation.
He joined the Cubs in 1983 as director of sales and promotions and became the team's marketing director in 1987. The innovative McDonough linked popular product giveaways, such as Beanie Babies, to the Cubs and was responsible for the creation of the Cubs Convention, which began in 1986 as a winter fan fest and became the prototype for other league and club events.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.