LEGISLATIVE Councillors yesterday approved the controversial post of Hongkong Commissioner of Economic and Trade Affairs in the United States, designated for the former Secretary for the Civil Service, Mr Barrie Wiggham. The 13-member United Democrats of Hongkong and liberal independent Ms Emily Lau Wai-hing abstained from voting when the proposal was put to the Legco Establishment Sub-Committee. United Democrat Dr Huang Chen-ya said he was not convinced that the new post should be a D8 post on the directorate pay scale. He argued that the present head of the Washington office only ranked D4 and said the post should be upgraded to D6 only. The new post won support after the Government aborted its plan to make it a departmental position, which would allow Mr Wiggham to stay in the job beyond the retirement age of 57. The original arrangement also drew fierce criticism after it was revealed that Mr Wiggham would be able to collect an immediate $5 million pension before he took up the post. Meanwhile, a proposal to create two permanent posts for the Governor's personal advisers was turned down by legislators. Instead, the sub-Committee approved two supernumerary posts for Mr Edward Llewellyn and Mr Martin Dinham that will end on 30 June, 1997. The administration maintained there was a justified case to increase the staff size. But legislators said it was Mr Patten's personal style that had caused the increased workload. They doubted if the future chief executive of the Special Administrative Region would need two personal aides. ''If Mr Patten needs his advisers, fine, lets create two supernumerary posts,'' said Ms Lau. ''But don't say it's Government House which needs it. For more than 100 years we didn't need any new posts in Government House,'' she said. Both Mr Dinham and Mr Llewellyn were brought to Hongkong as overseas contract staff for a term of 21/2 years and legislators agreed the posts should exist until the change of sovereignty. Mr Dinham, a former private secretary to Mr Patten, specialises in financial issues and relations with the business community. Mr Llewellyn, a former Conservative Party researcher, deals with political issues and constitutional development. He also drafts the Governor's speeches. Mr Dinham is Staff Grade B with a monthly salary ranging from $84,050 to $89,100. Mr Llewellyn is a Senior Administrative Officer with a monthly salary of between $47,420 to $54,635.