US investor Crest Financial increased its stake in US wholesale operator Clearwire to 8.34 percent from 6.62 percent, as it continued to oppose the company’s proposed merger with Sprint.

In a statement, Crest said that the investment, made directly and by its affiliates, “demonstrates its willingness to further invest in Clearwire and its confidence in Clearwire’s network build-out plan”.

The company late last week came out in opposition of the $2.2 billion Sprint merger proposal, filing a complaint which alleged that Clearwire and several other parties involved “breached their fiduciary duties by allowing Sprint to extract for itself the value of Clearwire’s high-speed, broadband spectrum to the detriment of Clearwire’s minority shareholders”.

Yesterday, it said it “continues to oppose the proposed merger of Clearwire with Sprint Nextel Corporation. Crest intends to pursue all avenues available to it including its lawsuit against Clearwire, Sprint and others in the Court of Chancery of the State of Delaware, to protect itself and other minority shareholders in Clearwire from the unfair dealings of Sprint and Clearwire in this matter”.

There have been reports that shareholders consider the $2.97 per share offered by Sprint undervalued the wholesale player, but that this was the maximum bid permitted by Softbank, the Japanese operator which is set to take a controlling stake in Sprint.

Last week investor Mount Kellett also expressed dissatisfaction with the deal, stating that Clearwire had been undervalued.

But, noting “uncertainty” over whether other investors will back the deal, ratings agency Fitch said it believes Clearwire’s standalone prospects were “bleak due to its constrained liquidity, limited access to new capital and inability to attract major new customers”.

It said: “Clearwire’s lack of additional strategic agreements with other operators, limited market access and substantial funding gap left the company heavily reliant on Sprint Nextel for further funding.”

Earlier this week, Sprint said it had entered into a “definitive agreement” to acquire the approximately 50 percent stake in Clearwire it does not own, although it noted that this is still subject to “the approval of a majority of Clearwire stockholders not affiliated with Sprint or Softbank”.

According to Reuters, the deal includes a “no-shop” provision, meaning Clearwire cannot seek other offers – although it can consider unsolicited approaches. It also includes a $120 million breakup fee, payable to Clearwire by Sprint if the acquisition does not go ahead.

Clearwire shareholders Comcast, Intel and Bright House Networks, which collectively own around 13 percent of Clearwire voting shares, have committed to back the transaction.