It's no secret that investment fund Crest Financial is steadfastly opposed to the merger agreement between Clearwire (NASDAQ: CLWR) and its parent Sprint (S). It has launched a proxy fight against it, sued in chancery courts to oppose it, and has lobbied the FCC to block it. Now it's filed a 40-page presentation with the SEC laying out its rationale for why shareholders should oppose the deal.

Crest Financial is Clearwire's largest independent shareholder with an approximate 8% stake in the spectrum owner.

Its main contention is that Sprint has low-balled the value of Clearwire's spectrum. Crest says the bids Sprint has received itself from both Japan's Softbank and DISH Network (DISH) are actually attempts to get at Clearwire, and quotes statements made by executives of those companies about their real interest.

"These statements confirm what Crest has been communicating to Clearwire's other shareholders for some time now: The battle for Sprint is really a battle for Clearwire's valuable spectrum, and that each of Sprint's suitors wants to divert the value of Clearwire's spectrum assets to itself so as to extract maximum benefit for itself to the detriment of Clearwire's minority shareholders," Crest Financial General Counsel David Schumacher is quoted as saying in a press release issued yesterday.

Because Clearwire says it needs to be acquired to forestall going bankrupt, Crest has offered $240 million in financing to keep it afloat.

Crest strongly urges Clearwire stockholders to vote against the Sprint-Clearwire merger using the gold proxy card.

A special meeting for Clearwire shareholders to vote on whether to accept Sprint's offer of $2.97 a share, worth $2.2 billion, for the shares it does not already own will be held on May 21. The Clearwire board laid out its case in favor of the merger earlier this week, saying its "stand-alone prospects are risky and highly uncertain." It urged shareholders to vote for the Sprint transaction using the white proxy card.