Updated 12/15/11 – 5:10 p.m.

CHICAGO (CBS) — Efforts to resolve differences over a new Aldermanic ward map broke down along racial lines Thursday, but top City Council officials say they’re hopeful they can reach agreement on a new plan floated this afternoon.

As WBBM Newsradio Political Editor Craig Dellimore reports, the latest U.S. Census showed Chicago’s Latino population grew dramatically from 2000 to 2010. Hispanic aldermen say the number of predominantly Latino wards also should grow.

LISTEN: WBBM Newsradio Political Editor Craig Dellimore reports

But that would mean some African American and white aldermen would lose majorities in their wards and long negotiations haven’t brought consensus on who gains and who loses and by how much.

The City Council’s Hispanic Caucus, led by Ald. Danny Solis (25th) formally filed their own ward map for City Council consideration.

“We have a map that we believe will pass muster, so to speak,” Solis said.

By Thursday afternoon, Rules Committee Chair Ald. Dick Mell (33rd) said there was a new map proposal and Ald. Howard Brookins (21st), chair of the council’s Black Caucus, said African American aldermen were on board.

“We continue to negotiate in good faith to try and come up with compromises that satisfy the needs of the Latino and African-American communities and also fair to our other colleagues,” Brookins said.

“I would say that there will be a map voted on by the Rules Committee prior to the City Council meeting in January,” Mell said.

A new map would need the support of 41 aldermen to be approved. If 10 aldermen unite behind an alternative map, the two maps would go to the voters in a ballot referendum during the primary elections in March. That could lead to an expensive referendum battle and possibly legal fight in court.