Clearwire founder Craig McCaw has resigned from his post as chairman of the company’s board of directors, according to a document filed last Thursday with the SEC.

McCaw’s decision to resign was not due to any disagreements over the company’s operations, policies or practices, Clearwire said in its filing. McCaw’s private equity firm, Eagle River Holdings, will nominate former Clearwire CEO Ben Wolff to take McCaw’s position.

The departure of McCaw comes amid Clearwire’s decision to raise about $1.33 billion in a debt offering to keep itself running during a cash crunch that has forced the company to lay off workers, delay its smartphone launch and reconsider build-out plans for its WiMAX network.

McCaw launched Clearwire in 2003, landing Sprint as a key investor in 2008. The company now offers mobile WiMAX services in about 70 U.S. markets but is struggling to maintain its head-start advantage amid competing mobile broadband offerings from Verizon Wireless, T-Mobile USA and MetroPCS.