In an escalation in the spat between Nokia and Qualcomm, the US International Trade Commission (ITC) has started an investigation into whether Nokia Corp. and Nokia Inc. have been involved in unfair practices against the CDMA giant.

The allegation is that the Nokias have been importing and selling handsets, wireless devices and other unspecified components that infringe one or more of Qualcomm’s patents.

Qualcomm said last month that it had asked the ITC to investigate Nokia and at the same time requested an exclusion order to stop importing of Nokia handsets that allegedly infringe Qualcomm’s patents.

It is also looking to prevent Nokia selling products that have already been imported and to halt the marketing, advertising, demonstration, warehousing of inventory for distribution and use of such imported products in the US for GSM/GPRS/EDGE networks.

The spat began last year when Qualcomm filed its allegations against Nokia Corp. and Nokia Inc. in San Diego. The firm claims Nokia infringed on eleven of its patents and one owned by its subsidiary, SnapTrack.

In June, Nokia ended its CDMA relationship with Sanyo. It also said it will cease its own CDMA research and manufacturing by next April. Qualcomm is the world’s leading supplier of CDMA processors.