The CDMA-based 4G technology, ultra-mobile broadband (UMB), has received another death knell. That’s because CDMA operator Verizon Wireless and its parent company Vodafone plc (Vodafone and Verizon Communications Inc. jointly own the operator) have decided to pursue the GSM-rooted technology known as Long-Term Evolution (LTE) instead as their 4G data network choice.

    Arun Sarin, CEO of Vodafone, and Verizon Communications Inc. Chairman and CEO Ivan Seidenberg explained their choices at a Goldman Sachs conference, citing the need for a common, global network technology.

    No timelines were mentioned, and Verizon continues to upgrade its existing CDMA network to EV-DO Rev. A. The two also mentioned that they would continue to trial and, in the case of Vodafone, use WiMAX where appropriate.

    The announcements are bad news for UMB, whose viability has already been called into question with Sprint Nextel’s choice to go with WiMAX over UMB for 4G. Sprint and Verizon are the biggest CDMA network operators in the United States; worldwide, the majority of carriers are based on GSM. That leaves a small market for UMB, making it potentially cost-prohibitive to design products for.