Comcast Corp. seems prepared to close the chapter on its ill-fated Clearwire Corp. experiment with a loss of $900 million to $1 billion.

Sprint Nextel Corp. and Clearwire announced a deal Monday for Sprint to purchase the shares it does not own in Clearwire for $2.2 billion, or $2.97 a share.

Some Clearwire investors have criticized the price, and Clearwire shares slumped 13.6 percent, 46 cents a share, to close at $2.91.

But Erik E. Prusch, Clearwire's president and chief executive officer, said in a conference call with analysts Monday that Comcast and two other strategic investors, Bright House and Intel Corp., supported the Sprint deal.

"We agreed to vote our shares in favor of the merger," Comcast spokesman John Demming confirmed Monday.

Comcast has taken regular write-downs on its $1.2 billion Clearwire investment in recent years as Clearwire lost money, and Comcast values Clearwire at zero on its books. So whatever gain Comcast realizes on a Sprint-Clearwire deal would eventually be recorded as a one-time gain.

Comcast, one of several big companies to invest in Clearwire as it was building out its WiMAX service nationally, owns 88.5 million shares. Those would be worth $263 million at Sprint's buyout offer.

As recently as 2008, Clearwire was considered part of Comcast's wireless strategy - the fourth product in its triple play bundle. Comcast, though, has switched allegiance to Verizon Wireless Inc. through joint-marketing agreements and the sale of wireless spectrum. Comcast realized an $876 million gain this year on the sale of the spectrum, which was another experiment in developing a wireless business. That venture was separate from Clearwire.

The Japanese company SoftBank Corp. has agreed to acquire 70 percent of Sprint for $20 billion. The Sprint deal for Clearwire, which owns substantial wireless spectrum, is contingent on SoftBank consummating its deal first.