At least half a dozen banks are working on proposals for financing a bid by Sprint Corp. for T-Mobile US Inc., sources told the Wall Street Journal.

According to the report, financing offers for a deal could be in place in January. Sources said last week that Sprint is contemplating a bid for T-Mobile that could come together in the first half of 2014. The deal could be worth over $20 billion. 

WSJ sources on Thursday said that SoftBank Corp.'s Masayoshi Son was in New York meeting with senior bank executives including Goldman Sachs Group chief executive officer Lloyd Blankfein. Masayoshi Son is the chief executive of Sprint owner SoftBank and the chairman of Sprint.

What was discussed during the meeting, however, remains unclear. The names of banks that are vying for the deal-financing business also couldn't be learned, the report said.

Sprint hasn't yet decided whether to move forward with a bid. The company is currently studying regulatory hurdles a bid would likely encounter. Sprint is more than 80% owned by Japan's SoftBank, WSJ said.