Hotel and property group Asia Standard International Group has conducted about 170 buy-backs of its own shares, worth $86.55 million, since the start of this year. Its parent, Asia Orient Holdings, a property developer, has also been raising its stake in the company by buying 23 million shares for $26.76 million. Market watchers said the buy-backs would tighten the grip of the ultimate controlling shareholder and managing director, Poon Jing, in Asia Standard. Mr Poon holds 71.05 per cent of Asia Orient which in turn holds 71 per cent of Asia Standard. Deputy chairman of the group, Lim Yin-cheng said: 'It's not unusual that a listed company repurchases its shares. We have no current plan to privatise Asia Standard,' he said. According to research group Disclosure, Asia Standard - which is chaired by Clement Fung Siu-to - bought back shares equivalent to 3.8 per cent of issued share capital between January 1 and August 29. The shares were bought between 99 cents and $1.63. The stock closed one cent lower at $1 yesterday. 'The on-going buy-back is also an effective tactic to prop up Asia Standard's share price,' one market watcher said. The parent company also purchased 1.1 per cent of Asia Standard between January 1 and July 29. Asia Orient and Asia Standard reported a combined $1 billion attributable profit in the year which ended in March, supported by sharp rises in operating profits.