Wireless service provider Sprint Nextel plans to pay up to $1.6 billion to Clearwire Corp over the next four years, potentially easing concerns about a liquidity crisis at Clearwire.

As a result, Clearwire said on Thursday it will pay $237 million in debt interest payment due on Dec 1.

Clearwire, which is majority owned by Sprint Nextel , said last month it may skip the payment to conserve cash as it needs almost $1 billion in new financing to keep operating and fund a network upgrade.

The payments from Sprint, which is also Clearwire's biggest customer, include the expansion of their current network agreement and the potential for an equity investment.

Sprint committed to providing more equity funding to Clearwire in the event of an equity offering. If Clearwire raises new equity between $400 and $700 million, Sprint will participate in the offering on a pro rata basis up to $347 million, consistent with its current voting interest.

(Reporting by Sinead Carew; Editing by Derek Caney)