Sprint Nextel today agreed to a merger with SoftBank of Japan which will give Softbank a majority stake in the US carrier in exchange for $20.1 billion. $12.1 billion of that will be distributed to Sprint stockholders, and the other $8 billion will be used "to enhance [Sprint's] mobile network and strengthen its balance sheet," according to the announcement.

SoftBank is the third-largest mobile carrier in Japan, just as Sprint is third-largest in the US behind Verizon Wireless and AT&T. SoftBank will receive a 70 percent stake in Sprint while Sprint shareholders will own the other 30 percent.

Sprint said the acquisition will allow it to improve operating scale and rely on SoftBank's experience in deploying LTE services as Sprint continues rolling out 4G in the US. "SoftBank’s cash contribution, deep expertise in the deployment of next-generation wireless networks, and track record of success in taking share in mature markets from larger telecommunications competitors are expected to create a stronger, more competitive New Sprint that will deliver significant benefits to US consumers," Sprint said. SoftBank's subsidiary in the US will be named "New Sprint," but Sprint headquarters will still be located in Overland Park, Kansas.

The boards of both companies approved the deal. After going through the regulatory process, they expect to close the merger in mid-2013. The announcement said Sprint will not be required to make any changes to its partnership with Clearwire.

It's a busy time for consolidation in the cellular industry. T-Mobile, which itself was nearly acquired by AT&T in a deal scuttled by antitrust concerns last year, agreed to merge with MetroPCS earlier this month.