Isis, the mobile payments venture of three top U.S. wireless network operators, said on Wednesday that Austin, Texas, would be among its initial service launch markets in the first half of 2012.

The venture of Verizon Wireless, AT&T Inc and T-Mobile USA is developing a service to let consumers pay for goods by waving their mobile phone, in place of their credit card, at a check-out terminal.

Isis will compete with Google Inc, which plans to bring out a mobile payments service this summer in conjunction with MasterCard Inc, Citigroup and Sprint Nextel Corp, the No. 3 U.S. mobile service.

Isis, which has yet to announce bank and payment network partners for its launch, had previously announced that Salt Lake City, Utah, would also be one of its first markets.

Verizon Wireless, the No. 1 U.S. mobile service, is a venture of Verizon Communications Inc and Vodafone Group Plc. AT&T plans to buy T-Mobile USA, a unit of Deutsche Telekom AG.

(Reporting by Sinead Carew; editing by Gerald E. McCormick)