26, 2008 an anonymous source stated that Sprint and Clearwire may get as much as $1 billion from Comcast and $500 million from Time Warner Cable in financial backing. Clearwire filed for its initial public offering with the Securities and Exchange Commission in May 2006. The company's underwriters included Merrill Lynch, Morgan Stanley and JPMorgan Chase. Trading began March 8, 2007 under the ticker symbol "CLWR" on the Nasdaq. Clearwire offered 24 million shares at $25 a share, and raised approximately US$600 million. Before the Sprint merger, Craig McCaw was the largest shareholder of the company with a majority of the shares. On May 7, 2008, Clearwire and Sprint Nextel's wireless broadband unit Xohm announced their intent to merge, combining Sprint's 4G WiMAX network (Xohm) with Clearwire's existing pre-WiMAX broadband network. Sprint owns 54% of the firm, with ex-Clearwire shareholders owning 27% – a consortium of Comcast, Time Warner Cable, Intel, Google, and Bright House Networks invested $3.2 billion and owns the balance. Clearwire and the cable companies will buy 3G mobile broadband from Sprint as MVNOs. Clearwire/Sprint Nextel officially launched Portland, Oregon, as the first market using the new service. Clearwire's 4G service was branded as CLEAR, except in those markets where the Clearwire name has already been established and where CLEAR service is not available. CLEAR 4G was available in 35 of the country's 40 largest metropolitan statistical areas, covering 130 million people. On March 9, 2009, Clearwire named Bill Morrow as CEO, succeeding Benjamin Wolff, who became co-chairman with Craig McCaw. Morrow, 49, stepped down as CEO of Pacific Gas & Electric Company. Morrow had previously held a number of senior positions at Vodafone. In April 2009, a class-action lawsuit was filed against Clearwire. The suit was dismissed in April 2009 but was appealed by the complainant. The suit claimed that the company's actual Internet connection speeds were slower than advertised and was sometimes unavailable. On December 31, 2010, McCaw resigned as chairman of Clearwire and was replaced by John W. Stanton. On March 10, 2011, Bill Morrow resigned as CEO and was replaced by interim CEO John W. Stanton. On August 10, 2011, Clearwire promoted COO Erik Prusch to president and CEO, and named John Stanton executive chairman. Clearwire stated that it might not honor a $237 million debt covenant due on December 1, 2011, in order to conserve cash. However, on December 2, 2011, the