LG today joined U.S. mobile operators in supporting chip vendor Qualcomm, asking federal courts to suspend Thursday’s U.S. International Trade Commission’s ban on new handsets containing Qualcomm CDMA radios.

The commission found in October that Qualcomm had infringed on rival chipmaker Broadcom’s patents related to power management, and Thursday it ruled that any new 3G phones containing the technology could not be imported into the U.S. The ruling could hit LG especially hard because of its large exposure to the CDMA market in the U.S. But almost ever vendor could be effected by the ban, which applies to both CDMA 1X and W-CDMA devices. Samsung has similar exposure, and Motorola uses Qualcomm chips in some of its newer phone models. Nokia, however, does not use Qualcomm chipsets though it is embroiled in its own patent licensing dispute with Qualcomm over W-CDMA technology.

Sprint and Verizon Wireless both rallied behind Qualcomm, claiming that such a ban would severely disrupt the flow of 3G phones in the U.S., crippling new high-speed data services just as they are starting to take off. Sprint and Verizon Wireless, being CDMA carriers depend heavily on Qualcomm chipsets. Its EV-DO chipsets reside in almost every 3G handset they sell. AT&T is less exposed since its W-CDMA handset lines come from a multitude of vendors, several of which do not use Qualcomm chipsets. Meanwhile, T-Mobile doesn’t have a 3G handset to its name as it is still in the process of building a UMTS network with recently acquired Advanced Wireless Services spectrum, but after it launches it the network it might find its choices for W-CDMA handsets limited if Qualcomm 3G handsets are banned.