A private equity firm specializing in distressed assets – a so-called "vulture fund" – says it is bidding $725 million to acquire the cell phone network assets of , topping a previous $650 million bid from Nokia Siemens Networks.

MPAM Wireless, an affiliate of Global Opportunities Partners III LP, said it submitted the bid for Nortel’s CDMA and LTE assets to Nortel and its creditors Tuesday.

MatlinPatterson is one of Nortel’s biggest debt holders. The formal announcement of a bid follows weeks of speculation that it would make a bid for at least some parts of Nortel.

The news came a day after Research In Motion, the maker of the popular BlackBerry wireless devices, also said it wanted to be a player in the bidding for assets of bankrupt telecommunications gear Nortel.

In a statement released Monday night, RIM said it was willing to pay nearly double what Nortel has been offered for key wireless assets by Nokia Siemens. However, RIM complained that it was being blocked from a possible acquisition and asked for government intervention.

Both companies are based in Canada.

Nortel employs some 2,000 people at a campus in Research Triangle Park, N.C.

CDMA, or code division multiple access, is a rival standard to the dominant cellular standard GSM, or global system for mobile, while LTE is a next-generation wireless network technology.

Nortel, a former telecommunications equipment powerhouse, sought bankruptcy protection in January and was planning to liquidate its business.

MPAM said in a statement that it believes a "New Nortel" can emerge from bankruptcy as a whole company.

"We are unwilling to accept and will actively take steps to prevent a ‘fire sale’ of Nortel’s core assets followed by the wholesale liquidation of the remaining businesses," it said in a statement.

MPAM said it had formed a team of advisers led by former Nortel executives Dion Joannou, Richard Piasentin and Tony Pirih. MatlinPatterson Global Advisers LLC is a $9 billion global private equity firm established in 2002.

Nokia Siemens, a 50-50 joint venture of Finnish handset maker Nokia Corp. and German industrial conglomerate Siemens AG, said it believed its bid was the best.

"We’re looking at the options but we really do just continue to believe that our offer is the one that ensures a long-term partner with global scale and proven experience in the telecom infrastructure space," said Nokia Siemens spokeswoman Chantal Boeckman.

A bankruptcy court-sponsored auction will be held Friday and a hearing on its results is expected on July 28