The Denver Nuggets and New Jersey Nets are advancing on another complicated multiteam trade proposal that would likely fit Carmelo Anthony’s(notes) criteria for signing a contract extension with the Nets, league sources told Yahoo! Sports.

Anthony is inclined to accept a trade and contract extension with New Jersey over his preferred choice of New York only if the Nets are able to bring back a package of significant talent with him, league sources involved in the talks said on Monday.

So far, there are trade scenarios that include a combination of Anthony’s Denver teammates – including forward Al Harrington(notes) – and other league players coming to the Nets.

“The way this is structured now, the Nets will significantly upgrade their team,” said one NBA executive involved in the talks.

Said a Western Conference executive whose team has pursued Anthony: “ ’Melo wants something similar to the Orlando deal, where he won’t have to go into New Jersey – or anywhere he’s going – without some help right away.”

Denver’s and New Jersey’s trade partners are still unclear, but league executives said the Nets and Nuggets are tweaking several possible proposals with multiple teams. For now, New Jersey general manager Billy King is preparing to send rookie forward Derrick Favors(notes), the expiring contract of Troy Murphy(notes), two or three future first-round draft picks and $3 million to Denver for minimally Anthony and Harrington. More Nuggets and Nets would likely be on the move, too.

Center Brook Lopez(notes) is the only Nets player not involved in any of the proposals, sources said.

The Nuggets’ sudden urgency to move the unhappy Anthony is the reason more teams have been calling lately, including two contenders who are willing to chase a championship with Anthony as a rental player, a league source said. The Nuggets could do those deals without consulting Anthony, because those teams aren’t requiring a contract extension with Anthony to make the trade.

Several executives involved in the talks believe a deal will come sooner than later. Denver has made clear to teams the bidding process will culminate long before the Feb. 24 trade deadline.

No deal is imminent, but sources involved in the talks believe that early January is a realistic target. The New York Knicks are still Anthony’s preferred destination, but so far there are no trade packages involving the Knicks that interest Denver. Knicks GM Donnie Walsh and Nuggets GM Masai Ujiri have been talking more in the past couple weeks, but sources said Denver officials still prefer the Nets’ multiple picks and Favors.

Nuggets president Josh Kroenke and Ujiri haven’t spoken in two weeks with Anthony about the approval process on a trade, a source said, but they’ve proceeded with an understanding that fattening a package for the Nets will go a long way toward getting him to sign an extension. When the time comes, the Nets are planning to have owner Mikhail Prokhorov personally sell Anthony on the Nets’ future in Brooklyn beyond 2012.

There are no teams involved in the pursuit of Anthony, including the Knicks, who believe Anthony is willing to pass on a contract extension before the trade deadline. With the owners determined to make sharp cuts into player salaries with a new collective bargaining agreement, Anthony’s willingness to accept a compromise sign-and-trade to get his three-year, $64 million extension illustrates his reluctance to enter free agency under a more restrictive salary structure.

The Nets would need to trade point guard Devin Harris(notes) to a third team to help bring back more talent, and somehow they have to come out of this trade with a veteran replacement. Chauncey Billups(notes) is a possibility, but there are questions about how much longer he can perform at an elevated level. Another player the Nuggets will likely move is shooting guard J.R. Smith(notes), who has drawn interest from the Chicago Bulls. Smith is making $6 million in the final year of his contract, and would love to end up with the Bulls, sources said. So far, Denver has resisted Chicago’s overtures on Smith because it may need to include him in a larger deal with Anthony. Bulls GM Gar Forman has been calling league personnel to do more research on the temperamental Smith, sources said.

The Nuggets and Nets had the framework of a four-team trade with Utah and Charlotte in October, but the deal ultimately fell apart. As involved as that scenario was, one executive involved in the past and present discussions described these as “a more complex, even bigger deal.”