Just weeks before the March 21 deadline to bid on the development rights at the West Side rail yards, the New York Jets have begun working with a coalition of developers to pull together a bid, The New York Sun was told.

Among others, Steven Roth’s Vornado Realty Trust and Stephen Ross of the Related Companies are likely to pitch in on the project, offering their own development scenarios should the area be rezoned from its current designation as a manufacturing zone, three officials familiar with the emerging bid told the Sun.

The idea is not just to expand the pool of cash available for a competitive bid for the air rights above the West Side rail yards, but also to craft a proposal that would allow the Metropolitan Transportation Authority to compare the Jets’ bid, point by point, with the bid expected from Cablevision owned Madison Square Garden.

“Cablevision was making a proposal that assumed 6.8 million square feet of development, and they had figured there would be residential buildings on the site,” the president of the Real Estate Board of New York, Stephen Spinola, said. “The Jets were bidding on only 2.4 million square feet. Because of the differential it was hard for the MTA to compare the bids.”

Early last month, Madison Square Garden, a fierce opponent of the plans of the Jets and the Bloomberg administration for a 75,000-seat domed stadium at the site, offered the MTA $600 million for development rights but said that would include the cost of building a platform over the Hudson Yards. According to the Garden’s preliminary offer, which could well be changed by the time the final bids are due 12 days from now, the MTA would have to share any cost overruns on the platform with Cablevision. Analysts said that put the Garden’s offer more in the neighborhood of $350 million than of the headline figure of $600 million. The offer envisioned residential development at the site, along with some commercial space.

The Jets, for their part, had offered the MTA $100 million in lease terms – a valuation they were willing to submit to nonbinding arbitration – and said the state-run authority would not have to shoulder any responsibility for the platform costs. Under the Jets initial scenario, the city would pay for the platform and the state would pay for the dome over the stadium, so that the facility could be used for conventions and concerts when the Jets weren’t playing a home game. Together that would come to $600 million in city and state funds.

Because the offers of Madison Square Garden and the Jets were so different, the MTA said in its Request for Proposals that it would be willing to entertain two kinds of bids. The MTA wanted a proposal based on current zoning, and then bidders could also suggest what they would do if conditions, such as a change in zoning that permitted housing, were modified.

Right now, the Hudson Yards is zoned with twice the number of square feet that the actual plot dimensions would permit. Instead of the 1.2 million square feet of development that would normally be allowed at the site, the state was going to override the current zoning to allow the Jets 2.4 million square feet of development.

Also confusing the issue is the need for a zoning change if housing is to be built at the site.

And a further complication is the MTA’s plan to offer the successful bidder a 49-year lease, not an outright sale. Analysts said that if the MTA were to make the lease longer – say, for 99 years – that could provide enough of an enticement to bring private developers into the project.

The Jets are expected to offer a bid that will suppose that they will be permitted to develop a larger footprint, something comparable to what Cablevision bid on, and then use that as a starting point to say how much that kind of broader development would be worth to them.

Land prices in Manhattan can run as high as $300 a square foot, though a reasonable estimate for that part of the Hudson Yards is probably between $150 and $250, real-estate analysts said.

Both the Madison Square Garden and Jets bids are far from completed. It is unclear how Cablevision might sweeten its offer, whether other bidders might emerge, and whether other developers could be added to the Jets’ roster. Among those who, in the weeks to come, may weigh in are the Sheldrake Organization, Sidney Fetner Associates, Macklowe Properties, Boston Properties, and Tishman Construction. All those companies are on the record as supporting the stadium project, analysts said.

The president of the Jets, Jay Cross, had hinted at his latest strategy to level the field two weekends ago when he said his organization would substantially increase its $100 million offer. Mr. Cross said the Jets would present “a competitive bid” by March 21 for the 13-acre rail facility.

“We’ve always said that we’ll pay what market value is,” he said. “These numbers people are throwing around are not really bids. People are not bidding $600 million. … Cablevision is really bidding about $300 million, so actually we’re all in about the same range.”

When the MTA conducted its appraisal of the rail yards, the figure it came up with for the whole property was $900 million, and the figure it arrived at for the stadium portion was $300 million.