MGM’s debtholders will have another week to consider a bankruptcy plan that would leave Spyglass Entertainmemt toppers in charge — a sign that a rival merger proposal from Lionsgate may have gained traction among the MGM lenders.

MGM announced late Friday afternoon that Oct. 29 is the new deadline for endorsing the Spyglass plan. The troubled studio said it had distributed a supplement to the solicitation package that was sent Oct. 7 with additional details about its financial information.

“In order to provide lenders sufficient time to review the supplemental information, MGM has extended the voting deadline by one week,” MGM said.

The materials have been sent to more than 100 MGM lenders for approval of the plan which calls for Spyglass toppers Gary Barber and Roger Birnbaum to manage a merged Spyglass-MGM operation following a pre-packaged bankruptcy. Earlier this week, Lionsgate unveiled its offer in which debtholders would emerge with 55% of the combined company.

MGM has continued to have no comment on how the new bid from Lionsgate would be handled. Lionsgate had no comment Friday on MGM’s one-week extension of the deadline.

The Spyglass plan calls for Barber and Birnbaum to manage a merged operation once MGM’s pre-packaged bankruptcy’s approved in court, wiping out the equity holders and leaving Spyglass with a 5% holding. That process is expected to take about 30 days once the filing’s made.

Lionsgate three largest shareholders — Carl Icahn, Mark Rachesky’s MHR Fund Management and Gordon Crawford’s Capital Research Global Investors — support Lionsgate’s merger proposal, which offers about $1.8 billion in stock and debt and leaves MGM debtholders with a 55% stake in the new company.

Lionsgate’s proposed merger would combine two of Hollywood’s biggest libraries and a significant presence in film and TV production and distribution.

Wall Street appeared to endorse the Lionsgate-MGM deal with Lionsgate shares rising 21 cents to $7.65 in trading on the New York Stock Exchange – a two-year high for the stock.

Also on Friday, Standard & Poor’s Ratings Services issued an improvement in its outlook for current B- credit rating for Lionsgate in the wake of the merger proposal. S&P had placed the rating on CreditWatch with negative implications in March after Icahn launched a hostile takeover offer.

“MGM has one of the industry’s largest film libraries, and it produces the lucrative James Bond films,” S&P said. “A combination with Lionsgate would bring significant additional film library assets and cash flow, but could entail substantial production funding and financing needs if the new company’s management pursues an active production strategy under the MGM brand.”