SINGER-actress Anita Mui Yim-fong yesterday launched an appeal with the Canadian Immigration Department to regain her landed immigrant status. Mui, 29, lost the permanent residency status she was granted four years ago when she attempted to enter Canada last week. Canadian officials said the singer was unable to prove that she had not abandoned Canada as her place of permanent residence. The eight-page appeal was sent to the Government by Toronto immigration lawyer Mendel Green, who represents Mui. Mr Green contended that Mui was a victim of recently-intensified border checks on Hong Kong Chinese entering Canada. ''They seem to be targeting Chinese businessmen for secondary immigration examinations,'' Mr Green said. He added that in their zeal to catch lawbreakers, immigration officials were penalising legitimate businessmen and personalities. Under the Immigration Act, a permanent resident is deemed to have abandoned Canada if that person is out of the country for more than 183 days in any 12-month period. Mui had been away from Canada because of business commitments, Mr Green said. When an inspector confronted Mui about residency, she conceded she had spent an extended length of time outside Canada. Officials then insisted Mui surrender her landed immigrant status, and apply for a work permit in order to follow through on her Canadian commitments - which included appearing at several charity events. Immigration Department spokesman Milton Best said there was no policy whereby immigration officers singled out people for inspection based on their ethnic origin.