PHOENIX -- An unofficial group of Delta Air Lines creditors wants to postpone a Feb. 7 bankruptcy hearing so creditors can take a closer look at a $9.87 billion offer from US Airways Group Inc. to buy the carrier.

The ad hoc creditors committee said in a written statement Monday that US Airways' cash-and-stock offer provides a "superior recovery for creditors compared to what they would receive under Delta's standalone Chapter 11 plan."

Atlanta-based Delta estimates it would be worth $9.4 billion to $12 billion if it emerges from Chapter 11 as a standalone company in the middle of the year.

The group, which represents creditors holding about $2.4 billion in claims against Delta, previously has called on Delta to cooperate with Tempe, Ariz.-based US Airways and give its offer a thoughtful and unbiased consideration. Now, the group is calling on the official creditors committee to ask Delta to do so.

In its statement Monday, the ad hoc committee urged Delta creditors to ask the bankruptcy court to postpone Delta's disclosure statement hearing one month as it considers the bid. US Airways has its largest hub in Charlotte, N.C.

If the disclosure statement gets approved as currently scheduled on Feb. 7, Delta would be able to start soliciting votes to approve its reorganization plan.

"We think the creditors should have a choice," said Anne Granfield, a spokeswoman for the ad hoc committee. "As it stands, unless the official committee comes out and says something, creditors won't have a choice."

Granfield said US Airways has offered to increase its bid for Delta if the creditors agree to postpone the meeting.

But US Airways on Monday denied reports it offered to add $1 billion in cash to its previous offer.

"We have not raised our bid," US Airways spokesman Phil Gee said. "The previous offer is still on the table and is set to expire Feb. 1."

Gee said the airline couldn't officially change its bid unless its governing board approved it, which it hasn't, and the Securities and Exchange Commission was notified.

US Airways has been seeking postponement of the reorganization hearing and has threatened to withdraw its bid if the hearing isn't delayed by Thursday.

US Airways launched a hostile takeover effort in November to buy Delta, which is under bankruptcy court protection from creditors. The official committee representing creditors hasn't said anything publicly since US Airways sweetened its offer earlier this month.

Previously, the committee supported letting Delta file to reorganize and emerge from bankruptcy protection as a stand-alone company.

Shares of US Airways rose $2.30, or 4.4 percent, to close Monday at $54.43 on the New York Stock Exchange.