AN investment broker who stole clients' shares and sold them for almost $1 million to finance her own market dealings was jailed for two years yesterday. Tsui Yin-yuk, 46, admitted selling tens of thousands of shares belonging to customers in the names of her brother and niece. Neil Mitchell, defending, said Tsui resorted to theft after her own dabbling on the stock exchange left her $220,000 in debt. She then stole $946,000, losing the remaining $730,000 through bad investments, Mr Mitchell told the District Court. But Judge Gould commented: ''To lose $730,000 she must have been an extremely bad investor and have invested millions.'' He jailed her for two years after she pleaded guilty to nine charges of theft between February and October 1992. Prosecutor Jenny Fung said Tsui worked as a broker for Union Bank Securities Ltd in Central. She said Tsui sold shares belonging to four customers under the names of her brother Tsui Wing-por and niece Phyllis Ho. Money received for the shares was then paid into their bank accounts to which she was a co-signatory. Her offences came to light after one cheated client, Chan Sau-ming, instructed her to sell 10,000 shares in Hang Lung Development which she had already sold. When she ignored his request, an internal investigation was launched which led to her sacking in March last year, Miss Fung said. Mr Mitchell said the four cheated customers had been reimbursed.