TWX was a trade magazine published by the Long Lines Department of AT&T Corporation. The magazine first appeared in June 1944 and was published sporadically, ceasing publication in March 1952 after 41 issues. TWX magazine took its name from the TeletypeWriter eXchange service, which was developed by AT&T Corp. in 1931. The TWX service was sold to Western Union in 1969, but it remained an industry standard until 1981, when it was converted to the Telex II system.