Hong Kong’s mobile operators could legally challenge government plans to auction off a portion of 3G spectrum that they hold.

South China Morning Post sources said CSL, SmarTone Telecommunications, Hutchison Telecommunications Hong Kong and PCCW’s HKT could oppose what is thought to be the preferred option of the Communications Authority.

The government originally presented three options for the 3G spectrum licences when they expire. These were to renew them at a reasonable fee, put up the existing 3G spectrum from public auction, or to auction off a third of the 3G spectrum held by each operator.

The plan will be decided in October, three years before the 3G spectrum licences expire, but the sources said the government has chosen the third option before operators have filed their submissions to the public consultation on the proposals.

The operators sent a letter to members of the Legislative Council’s panel on information technology and broadcasting last month, saying the plan is “at odds with international practices” in which incumbent operators’ licences were renewed when they expired.

The letter added it will have “a serious adverse impact” on consumers as it could lead to an inability to make or receive calls, dropped calls, slower data speeds and increased service degradation in shopping centres and on the MTR metro system.

They also warned that the uncertainty created is likely to prompt the operators to reduce investment in their 3G networks.

Legislator Charles Peter Mok said the government wants to avoid being seen as colluding with the incumbent operators and feels the addition of an operator to the market could increase competition.