Sprint filed a lawsuit Tuesday alleging that three other telecommunications companies stole patents and trade secrets from the Overland Park-based company.
The lawsuit, filed in Johnson County District Court, names as defendants Charter Communications, Bright House Networks, Time Warner Cable, and two former Sprint employees.
Court documents allege the two former employees disclosed trade secrets to Bright House shortly before leaving Sprint and joining Bright House.
The patents and trade secrets were related to Sprint's Voice over Internet Protocol technologies, which enable phone calls over the internet instead of a phone line.
Sprint spent hundreds of millions of dollars developing its VoIP network and was beginning to recoup its investment when Bright House met with Time Warner Cable, one of Sprint's largest customers. Time Warner began planning to leave Sprint and with Bright House's help, build its own VoIP network, the lawsuit alleges.
More than 3,500 Sprint documents, including network designs and financial information, were found in Charter's possession, the lawsuit said. Charter Communications acquired Bright House in March 2015.
Charter Communications declined to comment.
Last week a federal judge approved the merger between Sprint and T-Mobile, which will shrink the number of major U.S. wireless companies from four to three.
