Former Hong Kong chief executive Donald Tsang Yam-kuen was sentenced on Wednesday to 20 months in prison for misconduct in public office, making him the highest-ranking former government official in the Hong Kong Special Administrative Region to be sent to jail.

Tsang was found guilty on Friday of misconduct for failing to declare a conflict of interest when he approved an application for a radio broadcasting license from broadcasting company Wave Media. At that time, he was in negotiations with a businessman, who was a major shareholder of Wave Media, over a rental apartment in Shenzhen, which Tsang intended to use after he retired.

He was acquitted of a second count of misconduct.

Tsang, 72, will also face a retrial on a bribery charge in September, in which he was accused of receiving an advantage from the businessman - a HK$3.5 million ($451,000) renovation of the apartment, allegedly at the request of Tsang's family.

A charge of a chief executive accepting an advantage carries a maximum of seven years in jail and a fine of HK$500,000.

Justice Andrew Chan Hing-wai stressed the seriousness of the conviction that lies in Donald Tsang's position as former chief executive of Hong Kong, and that the "breach of trust was an important and significant aspect in his criminality".

The judge said he planned to sentence Donald Tsang to 30 months in jail, but took off 10 months because of his "good character and contribution to Hong Kong".

Donald Tsang's defense lawyer, Clare Montgomery, asked the court not to start the retrial on a bribery charge until the appeal was settled on grounds that the new jury selected for the retrial might be influenced by the conviction.

However, the judge disagreed with her, saying that on that basis, many people would have the chance to avoid a retrial.