UPDATED 12/4: The Thai government rejected AIS’ offer to match Jas Mobile’s failed bid for a 900MHz licence and has called for the regulator to bring the re-auction date forward by a month to 27 May.

Market leader AIS, the second highest bidder for the 4G block, told the telecoms regulator last week it would pay THB75.65 billion ($2.1 billion) for the 10MHz of 900MHz spectrum forfeited by Jas Mobile, but the government rejected the offer to avoid allegations of favouritism, the Bangkok Post reported.

National Broadcasting and Telecommunications Commission (NBTC) chairman Takorn Tantasith said a re-auction offered the best option for all sides and would avoid possible legal challenges by other parties, which would cause further delays.

True had urged the NBTC to push ahead with the planned re-auction in order not to lose credibility. The Post reported True CFO Noppadol Dej-Udom as saying the re-auction can expect serious competition between AIS and dtac, leading to higher bidding prices. He didn’t say if True plans to participate.

NBTC’s draft rules had barred True, which won spectrum in both the 900MHz and 1.8GHz bands last year, from participating, but the government said all operators can join except for Jas Mobile.

Next month’s re-auction will have a reserve price of THB75.65 billion, the winning bid by Jas Mobile, which forfeited the 4G licence last month when it couldn’t meet the payment schedule.

The prime minister is expected to approve the updated draft rules today.