STOCKHOLM, Jan 19 (Reuters) - Swedish telecom regulator PTS on Tuesday began auctions of 5G spectrum which were delayed by a court battle with China's Huawei after it banned the company from its next-generation networks.

Hi3G Access, Net4Mobility, Telia Sverige and Teracom have been approved for participation in the 3.5 GHz and 2.3 GHz spectrum auctions.

The bidders are units or joint ventures of telecom operators such as Telia, Tele2, Telenor and Tre.

The auction was delayed for a security review and then over a lawsuit filed by Huawei.

Sweden followed Britain in banning Huawei equipment from its 5G networks, citing national security risks.

PTS had initially given companies taking part in 5G spectrum auctions until Jan. 1, 2025 to remove Huawei and ZTE equipment from their existing infrastructure and core functions.

PTS took the decision based on judgments from the armed forces and Swedish Security Services, but Huawei then offered to meet any requirement the government might set on 5G network equipment and take other measures to mitigate concerns.

Two other appeals in relation to PTS's ban are still pending in courts. (Reporting by Supantha Mukherjee and Helena Soderpalm; editing by Jason Neely)