Edmonton Oilers owner Daryl Katz finally broke his silence Thursday to reveal that the $100 million he promised for a new downtown arena has some strings attached.

In an interview with 630 CHED, the Oilers official broadcaster, Katz admitted what he had told Edmontonians in the past isn't exactly the case today.

"Precisely how and in what context the $100 million is to be contributed depends on a variety of issues, the most important of which is who owns the arena," Katz said.

But that qualifier wasn't mentioned when he bought the Oilers. Around that same time, Katz wrote in a press release, "I will commit my time, energy, and on the order of $100 million in additional funds towards a new building."

Now, his move has changed. Katz wants the city to pay for and own the $400 million downtown arena, claiming property tax on additional development in the area should pay the bill in the long run.

"Our contribution in that regard can best be leveraged in facilitating a tax base that can assist the city in paying for the arena over a long period of time," said Katz.

Mayor Stephen Mandel admits council was surprised that the previous $100 million offer has changed, but he says he's waiting for a formal application from the Katz Group before saying too much publicly.

"We need to wait and see what the final proposal is. It might have been handled a little better but that's up to the Katz Group."

City planners tell CTV News they are working on crunching some of the numbers related to the downtown arena proposal, but admit it's been a difficult task. They say they've met informally with the Katz Group.

The Katz Group unveiled its proposal to spruce up Edmonton's downtown on Tuesday. The group says by 2014, it would like to have in place a new state-of-the-art arena, two office towers south of 104th Ave., a community rink, two hotels, a new casino, new student housing, and new shops.

Plans are also in place to construct a pedway or a what the group calls a "winter garden", which will allow people easy access over 104th Ave. and will serve as the focal point of the new district.

With files from Scott Roberts