Japanese communications provider Softbank began discussions for a 70% stake in Sprint in October last year, but it is now in a bidding war with Dish Networks, after the satellite TV provider put forward a rival offer for the US operator.
The Financial Times reports that Softbank is in preliminary talks with Deutsche Telekom, which owns a 74% stake in T-Mobile USA, over a potential acquisition.
Softbank has previously held discussions with Deutsche Telekom over a potential acquisition of its stake in T-Mobile USA, but this fell through when it merged with MetroPCS.
Sprint shareholders are reportedly set to decide on the winning offer on Wednesday this week.