With Catherine Debo's announcement that she is leaving her job running Madison Metro Transit, Mayor Dave Cieslewicz is looking for a manager to increase ridership and address financial shortfalls in the city's bus system.

Mayoral spokesman George Twigg said today the ideal candidate would be able to continue to boost the number of riders both within the city and through expanded regional efforts. Also, he said, the next manager should be "someone who can bring some creative thinking into some of the financial challenges that Metro has faced in recent years."

Debo announced her decision to leave Metro as its general manager in an e-mail to reporters on Thursday. Her contract, which was up for renewal in April, is being extended until September, although the terms of it have yet to be finalized, Twigg said. Her salary is $88,292.

Debo and the mayor had been in contract discussions for the past few months, and she wrote that she "came close to accomplishing what I'd wanted to accomplish during my tenure."

She said that she is "torn between two interests - to complete all of the initiatives I've launched and to move on to new challenges."

In the remaining months, Debo said she wants to see through the implementation of restructured west side and south side routes.

Debo said she was "not dissatisfied with the pace or tone of my discussions with the mayor concerning extension of my contract" and later added that she and the mayor had discussed announcing her departure during a news conference, but she decided against it.

Twigg said he could not describe the conversations between Debo and the mayor.

"Those were private discussions. They were amicable at the end of the day," he said.

Asked whether the talks began amicably, Twigg said, "the talks were amicable," adding, "the end result is that Catherine is leaving in the fall."

The timeline for finding a successor is uncertain, Twigg said. "She made the announcement earlier than had been planned," he said.

In the last year, Metro faced a financial gap of up to $1.4 million. After raising fares for many riders and getting a 4 percent increase to $8.6 million in city funding, the department still had a gap of about $560,000 last fall in its overall budget, which includes federal funding of $43.4 million.

Debo seemed to have few allies on the city's Transit and Parking Commission, which oversees her department. Members of the commission, such as Ald. Jed Sanborn, have criticized Metro as "broken" and "a product of exploding costs."

As rumors grew that Debo was leaving, Sanborn declined to comment on Debo's performance. Earlier this week, Ald. Ken Golden, also a member of the Transit and Parking Commission, answered "no comment" when asked if Debo's contract should be renewed.