In 1928, Electrical Research Products, Inc. (ERPI) was created as a subsidiary of Western Electric, for the design, sale, and service of audio devices, in particular, theatre sound equipment.  Because of antitrust actions by the government, ERPI was spun off in 1937, and became the Altec Service Company.  "Altec" was short for "All Technical".  For several years, Altec continued to sell existing stocks of Western Electric equipment, as it ramped up it's production capabilities and, in 1941, acquired the Lansing Manufacturing Company, to become Altec-Lansing. 

The microphone shown here is marked with the original Western Electric name and model number (on the bottom), but had the Altec name added on the side.  Later Altec products were marked only with the Altec name. 

Western Electric markings on bottom.

Altec markings on side.