Start-up Convergent Networks, a maker of high-speed network switches, said it plans to acquire telecommunications software provider Technology Control Services (TCS) in a stock merger transaction. Though terms were not disclosed, Convergent chief executive John Thibault said the deal's worth was "significantly north of $100 million." The 100-employee TCS, based in Fort Lauderdale, Fla., makes software called a "softswitch" that allows a communications network operator to easily build and provision new software services for its customers. The company will offer the combined technology in the fourth quarter of this year, according to executives. Convergent currently has four announced customers for its set of broadband switching devices.