The weird battle over the cable industry’s top supplier of porn channels and videos just became a little more interesting. New Frontier shares rocketed 11.8% to $1.70 today after its largest investor, Longkloof Limited, raised its purchase offer to $1.75 a share from $1.35 — valuing New Frontier at about $28.3M. The new offer tops a separate $1.50 a share offer from Luxemburg-based porn company Manwin Holding, which last year bought Playboy’s TV and digital businesses. In April, New Frontier hired Avondale Partners to help sort through strategic alternatives. Longkloof, which owns about 15% of New Frontier, has said that it will nominate a slate of potential directors but insists that it wants to buy the company, not take control in a proxy fight. New Frontier produces VOD features, it also offers the Penthouse TV premium channel and pay-per-view services packaged as The Erotic Networks (or TEN) that include Xtsy, Juicy, and VaVoom.

In a letter today to the New Frontier board, Longkloof challenged current management’s willingness to sell: “Are they looking to further delay the process (such as by delaying the annual meeting) or force a time consuming and value-destroying litigation when we clearly have the best interests of all shareholders in mind? Shareholders should not stand by while the Board of Directors takes steps to further entrench themselves. We hope that the Special Committee will finally take its fiduciary duties seriously and not continue to use our offer as a justification for paying itself additional fees.”