Three senior executives of a cleaning company were convicted yesterday by a District Court judge of defrauding the Leisure and Cultural Services Department by paying workers less than the amount stated in the contract. Yu Lai-yin, 42, general manager of Yu's Tin Sing Enterprise, the company's contract manager, Ng Lam-tim, 51, and district manager, So Mun-yu, 28, were each found guilty of one count of conspiracy to defraud. Under the contract, the company was supposed to pay each worker no less than $5,081 a month. But the ICAC investigations revealed that the workers were paid less than that, the court heard. The department had been misled into paying fees of about $1.3 million for the company's services in January and February last year, prosecuting counsel Juliana Chow told the court. Deputy District Judge William Ng Sing-wai adjourned sentencing to January 21.