The Wall Street Journal on Friday reported that Sprint Corp. is considering a bid for rival T-Mobile US. Sprint is America's third-largest carrier, and the move is a test in order to test U.S. Regulators's willingness to have just 3 major carriers in the U.S., the report said, adding that the bid could be expected in the first half of next year.

Sprint and T-Mobile rank behind Verizon Wireless and AT&T Inc. in wireless customers.

Such a deal could be worth more than $20 billion, depending on how much of a stake Sprint buys, the newspaper reported.

Two years ago the Justice Department rejected AT&T's $39 billion deal to buy T-Mobile. So Sprint's possible bid could be an ultimately fruitless merger deal.