Taiwan’s National Communications Commission (NCC) is planning to auction off an additional 190MHz of TDD and FDD spectrum by the end of Q3 2015 and expects to raise at least TWD15 billion ($502 million).

Six mobile operators are expected to bid for 140MHz of FDD-LTE spectrum and 50MHz in the TDD band.

The LTE auction last year raised TWD118.6 billion ($3.96 billion). Six players – Chunghwa Telecom, Far EasTone, Taiwan Mobile, Ambit Microsystems, Star Taiwan and Asia Pacific Telecom – purchased a total of 135MHz of spectrum in the first 4G auction a year ago.

Meanwhile, Ambit Microsystems, which together with Hon Hai Group obtained 20MHz of LTE spectrum last October, is looking to sell off a 15 per cent stake to Taiwan Mobile for TWD2.98 billion ($99.7 million).

As part of the deal, which requires approval by the National Communications Commission, Ambit would also sell Taiwan Mobile 5MHz of LTE spectrum for TWD3.43 million. This would give Taiwan Mobile 35MHz, which is equal to Chunghwa Telecom’s LTE holding.

The deal is prompted by Ambit’s plans to merge with Asia Pacific Telecom (first buying a 15 per cent stake). But Ambit also needs to divest 5MHz of LTE spectrum to comply with the 25MHz cap on spectrum in the 700 and 900MHz bands, the China Post reported.

Ambit doesn’t yet have a 4G license but its 4G rollout plan has been approved.