Vietnamobile has become Vietnam's fifth mobile operator to launch 3G services.
The company, a joint venture between Hanoi Telecom and Hutchison International, has launched a HSPA+ service with peak connection speeds of 21.6Mbps, SGGPreported.
The operator is targeting Vietnam's major cities first, starting with Ho Chi Minh City, followed by Da Nang and then Hanoi.
Vietnamobile had bid for a separate 3G license in 2009 in a consortium partnership with state-owned EVN Telecom. EVN launched 3G services in June 2010.
The other Vietnamese 3G service providers are state-owned Vinaphone, as well as Mobifone and Viettel.
Viettel is estimated to have the largest overall mobile market share in Vietnam, with around 36% of the market, followed by Mobifone and Vinaphone.
Hanoi Telecom has been a vocal opponent of the government's plan to allow Viettel to merge with EVN.