AN estate agent who took part in the ''well-planned and well-executed'' kidnapping of a businessman was yesterday sentenced to seven years' jail. Wong Hing-tong, 29, broke down and cried in the dock after the High Court jury found him guilty of conspiracy to forcibly take away factory owner Mr Tse Yuen-lung, 37, against his will for a ransom of $3 million, which was later reduced to $300,000. Wong's counsel, Ms Alice Tsang, said in mitigation the ransom was not a big amount and it was not a ''bad type'' of kidnapping. The victim was detained only for one night, she said. Wong was a waiter before leaving for Holland to join his two brothers. He returned after three years in 1989 and worked in a real estate agency. Mr Justice Saied, in sentencing Wong, said he found that not only was the defendant a willing partner in the conspiracy, but he had carried out his assignment to collect the ransom. The judge also found the victim was manhandled and beaten in order to obtain the ransom and his wife was made to suffer an experience which was ''extremely unpleasant and undignified''. Evidence called by deputy Crown prosecutor Mr Anthony Duckett, QC, was that Mr Tse's wife was stripped half-naked and photographed before she was sent home by her husband's captors to collect a $300,000 ransom. The victim had also been severely beaten because he could not remember the code number of his bank card. The kidnap took place on January 31, 1991, when Mr Tse and his wife had gone to his garment factory in To Kwa Wan. At about 1.40 am, he went to move his Mercedes-Benz from the car park. Three men overpowered him and put him in the boot of the vehicle. Wong's defence had been that he had not been present at the kidnapping.