TXI settled its patent infringement litigation against Southdown (now a unit of Cemex). TXI filed suit against Southdown in 1999 alleging patent infringement of TXI's CemStar technology, which was developed in 1994 as a means to increase production in kilns without requiring significant capital investment. TXI license CemStar to a number of U.S. cement producers. In a press release, TXI said that as part of the settlement agreement Cemex signed a national CemStar licensing agreement with TXI.