LightSquared has until 5 p.m. Monday to negotiate a deal with lenders to keep from defaulting on loans. Sources told the newspaper that lenders are unlikely to grant LightSquared an extension to a debt-term violations waiver that expires at that time.

Hedge-fund manager Philip Falcone, whose firm Harbinger Capital Partners is the venture's primary backer, and lenders have been unable to agree on how much ownership LightSquared should turn over to lenders, the sources were quoted as saying. Other terms of any potential deal are also sticking points in the negotiations, the sources said.

LightSquared's board was tentatively planning to meet Sunday to talk about whether to authorize the bankruptcy filing, which sources said is expected to be filed before Monday evening.

Lenders have sought an independent board that didn't include Falcone to oversee LightSquared and although he "tacitly agreed" to that, financial restructuring of the venture "created a gulf" between the sides, the Journal reported. Lenders also wanted to hold Falcone liable for a bankruptcy filing under circumstances not specified in the newspaper report, which said that Falcone would not agree to those terms given that the he would no longer be on the board or be making decisions for LightSquared.

After Harbinger acquired SkyTerra and part of TerreStar, which are both satellite mobile data providers, it formed LightSquared in 2010. LightSquared operates satellite-based services and had planned to built a land-based LTE-network and sell on a wholesale basis capacity of both systems to other carriers. However, the U.S. Federal Communications Commission announced in February its intent to kill the land-based component of the initiative because tests showed it would interfere with GPS receivers.