Sprint and Clearwire are close to inking a deal that will extend an existing network-sharing agreement an additional 3-5 years, Bloomberg Businessweek said Friday. The current agreement will terminate at the end of 2012. Allegedly, the deal is not final and could still fall through.

If it is finalized, Sprint is poised to pay less for access to Clearwire’s network than it currently does. Clearwire has been seeking additional funding to help it build out a 4G LTE network, which is expected to cost $600 million, but Sprint will not provide any of the financing. “This would likely help [Clearwire] get funding, because it would provide increased visibility into revenue-getting opportunities and reduce the risk profile,” Mizuho Securities analyst Michael Nelson told Bloomberg. Clearwire most recently began courting AT&T and Verizon Wireless in a bid to raise cash for its new network.