Updated at 12:53 p.m.

Six months after the Vikings stadium deal paved the way for a public/private renovation of Target Center, Minneapolis' chief negotiator says the Timberwolves and the arena's operator still won't say how much they will pay.

The Timberwolves contend that's because the city unexpectedly changed the ratio of public to private funds this spring, which delayed the entire process. The split is now expected to be about half and half.

The "implementation committee" for the estimated $100 million renovation of the city-owned building -- the team hasn't agreed to that number -- has already met twice. But the city's lead official on the project, Jeremy Hanson Willis, expressed frustration Tuesday night that there wasn't a deal.

“We’ve said that we need to have significant private contribution in order for us to do this renovation," Hanson Willis said after a meeting of the committee. "And we don’t yet have confirmation about to what degree the private sector is going to contribute to this.”

The city wants the project to be roughly a 50/50 split between public dollars and the private dollars, put up by the Timberwolves and operating company AEG. The publicly stated expected cost of the project recently fell from $150 million in 2011 to about $100 million today.

Ted Johnson, a senior vice president of the Timberwolves, said city officials initially projected that the private sector would only pick up about one third of the tab. That changed this spring when city said it would be half and half, which team officials read in the newspaper.

"We’re dealing with the new ratio that’s been put to us," Johnson said. "We have twice stepped up our private commitment from where we started a year and a half ago.”

Johnson declined to say where the team's contribution stands, or what they would like the cost of the project to be. But the team has recently put forward a new funding framework that includes a 50/50 split, he said.

The city has already entered into a $20,000 consulting contract with AECOM, an agreement that also includes Mortenson Construction. A timeline devised by Mortenson, handed out at Tuesday's meeting, projects that construction will begin on May 10, 2013.

Hanson Willis said while a lot of the discussion centers on the total cost of the project, there's also no agreement between the Timberwolves and AEG about how they will divide the private expenses.

“I wish we would have had an agreement by now," Hanson Willis said. "It would have made the work of this committee and a lot of our work easier.”

Johnson agreed that the cost remains in limbo. “We haven’t agreed upon a $100 million project," Johnson said. "We’re still negotiating the project. I think there’s still differences of opinion of what the scope of the project should be.”

By contrast, the Vikings stadium implementation committee did not start meeting until the Legislature and City Council had approved a broad payment outline for the project.

The renovations are needed to improve many facets of the 22-year-old building, which lacks the amenities of its peers in the metro area and the NBA. Behind-the-scenes improvements are also necessary, such as additional loading bays, more than one freight elevator, and space to store bleachers -- they are currently housed outside when not in use.

AEG's Steve Mattson said he would defer to the city on how to characterize the process, but said he believes the pace has been "reasonable." AEG's role is slightly different than the Timberwolves, since the city has hired them to be the manager of the building.

“I think we’ll get there and we need to get there," Hanson Willis said. "And we’re not there yet and I wish we were.”