BANGKOK, May 9 (Xinhua) -- Thailand's Assets Examination Committee (AEC) has resolved that ousted Prime Minister Thaksin Shinawatra is guilty of malfeasance in office as he gave undue market advantages to telecom giant Shin Corp then owned by his family, the Thai News Agency (TNA) reported Wednesday.

    The report quoted AEC Secretary Kaewsan Atibhodi as saying that the panel, which is involved in the Thaksin-related graft investigations, believed Thaksin had abused his power during his five years of premiership from 2001 to 2006 to bring about undue and inappropriate gains to Shin Corp by turning a portion of the concession royalty into excise tax.

    According to Kaewsan, during the tenure of former Information and Communication Minister Suraphong Suebwonglee under Thaksin's administration, telecom firms under concessions granted by state-owned TOT and CAT Telecom companies were required to pay 10 percent in excise tax, plus 15 percent in royalty fees.

    Earlier, the full royalty fee rate was set at 25 percent. Under the new measures, the mobile operator Advance Info Services (AIS),a Shin Corp affiliate, was obliged to pay only a 25-percent tax all together, while smaller telecom firms without state concession,like the DTAC, faced a 30-percent excise tax.

    Kaeswan said such tax measures had undermined the competitive edge of new and small telecom firms, which would otherwise have offered alternative, price-competitive services to the public, and enabled AIS to dominate the telecom sector.

    Such taxation was adopted in apparent breach both of the Constitution and a Telecommunications Act which called for free and fair competition in telecom services, Kaewsan said.

    Kaewsan said the Shin Corp stocks, 49 percent of which was then owned by the Shinawatra family, had sharply risen upon the introduction of the excise tax for telecom firms and culminated in a surge of the former prime minister's wealth from 20 billion baht(583.8 million U.S. dollars) to more than 70 billion baht (2.043 billion dollars) during a five year period.

    The Shinawatra family sold their majority holdings at Shin Corpin January, 2006 to Singapore's state-controlled investment company Temasek Holdings in a controversial deal, which induced large-scale street protests in Bangkok by anti-Thaksin camps and prompted a review into the transfer by authorities after the Sept.19 coup deposed Thaksin of the premiership.