Clearwire managed to add a record number of subscribers in the third quarter – 1.9 million, mostly wholesale – and reported a decent quarter overall, but its financing requirements are keeping investors from getting too excited.

Clearwire President and CEO Erik Prusch said the company continued to add retail customers, as well – 35,000 in the third quarter. The company now expects to end the year with more than 10 million total subscribers.

In a conference call with analysts yesterday, CFO Hope Cochran said the company expects it can fund the business for the next 12 months, but it still needs to raise money to meet its obligations. The amount of capital it needs depends on expectations for future wholesale revenue, she said.

Sprint's recent steps to limit subscriber usage on Clearwire's network, the launch of a 3G-only iPhone and its commitment to sell mobile WiMAX devices only through 2012 are factors in that. Thus, the company did not update its guidance on funding needs and its ability to generate positive EBITDA in the near term.

Prusch said the company has made progress in its dealings with majority owner Sprint; the two entered a non-binding technical agreement on their respective LTE deployments. But as for raising additional capital from Sprint and/or other parties, Clearwire didn't have anything new to announce.

While discussions continue, "there remains a gap," he said with regard to Sprint.

Last month at 4G World, Sprint said 20 percent of its traffic will run over Clearwire's WiMAX network by the end of this year, and its 4G customers, branded as Sprint 4G but using Clearwire's network, are Sprint's most satisfied ever. But when asked during the Q&A, Prusch declined to get into specific sticking points between the two.

In a research note after Clearwire's results, Stifel Nicolaus senior telecom services analyst Christopher King said Clearwire turned the corner on sub growth, but capital concerns remain. Stifel maintains a "hold" rating on the shares.

"Given its relatively late start with LTE and, [more importantly], continued financing questions, we find it difficult to get excited about the story," King said.

In a blog post today, BTIG Research analyst Walter Piecyk said BTIG analysts expect Clearwire to post positive EBITDA for the first time in the first quarter, in large part due to the elimination of its postpaid business and the related customer acquisition costs.

BTIG estimates Sprint will sell 1.75 million iPhones in the fourth quarter and 1.6 million 4G phones. "We believe Clearwire is a far cry from the zero net additions potential that has been noted by some of our peers."

Clearwire reported a net loss from continuing operations of $83.5 million for the quarter. Revenue was $332.2 million, a 134 percent increase over the third quarter of 2010. Third-quarter 2011 wholesale ARPU was $6.20, up from $4.46 in the third quarter of 2010, and wholesale churn was 1.5 percent in the most recent third quarter, compared with 1.3 percent in the year-ago quarter.

The company now expects capital expenditures in 2011 to be less than $300 million, about $100 million lower than its previous guidance.

Clearwire shares were trading down about 10 percent early this morning, to $1.83.