One more lawsuit may spell the end for Vonage (VG)

Deaths come in threes and the latest lawsuit against Vonage Holdings Corp. (NYSE: VG), the VoIP pioneer, may just put it under. It is the third such suit by a major telephone company.

Vonage has now lost or settled patent infringement suits brought by Verizon Communications Inc. (NYSE: VZ) and Sprint Nextel Corp. (NYSE: S). Each loss has brought a one time payment and royalties on future revenue.

An SEC filing by the VoIP company disclosed that an action has been filed buy AT&T Inc. (NYSE: T), which accuses Vonage of "violating a single patent that lets users access an Internet phone system using a standard phone device," according to The Wall Street Journal.

Vonage opened at $17 on its IPO in 2006. The stock is lucky to hold $1 now. And, the AT&T suit may be the end of the line. In the June quarter, the company had an operating loss of $33 million on $20 million in revenue. The company's cash was down to under $350 million.

It is Chapter 11 time for Vonage. One of the large cable companies would probably be willing to pay enough for the company to pay off lawsuits and, perhaps, leave a few pennies for the shareholders.

Douglas A. McIntyre is an editor at 24/7 Wall St.