Shares of Ixia rose to a 52-week high Monday on news that the telecommunications company was increasing its fourth quarter guidance due to the performance of two recent acquisitions. The Calabasas company said it was raising its revenue guidance to a range of $123.5 million to $124.5 million, above its previously stated guidance of $118 million to $122 million. Its initial guidance was still above analyst estimates. The company cited the strong performance of two recently acquired companies, Anue Systems Inc. and BreakingPoint Systems Inc., as one reason for the change. The company is slated to report earnings Feb. 6 after market close. “Ixia delivered an impressive fourth quarter with strong momentum across all of our solutions,” said Chief Executive Vic Alston, in a prepared statement. “The integration of our Anue and BreakingPoint acquisitions is tracking well, and we are increasing our presence at enterprise and service provider accounts.” The company makes network testing products. Its largest client is Cisco Systems Inc., followed by AT&T Inc. It has operations in 30 countries. Shares opened at a 52-week high of $18.15 and rose to $19.50 in trading on the Nasdaq before settling down to close at $19.24, for a gain of $1.58, or nearly 9 percent.