HONG KONG - HONG KONG stock exchange said Tuesday it would push ahead with a new measure designed to make insider trading more difficult, despite massive opposition from listed companies and tycoons.

However, in a bid to allay concerns, the exchange decided to defer the implementation of the rule from January 1 to April 1 next year.

The controversial measure will effectively extend the period banning directors from trading shares in their companies from the present four weeks before the company's earning announcements to up to nine months.

'The Listing Committee strongly believes that the rule is in the long-term interest of Hong Kong and in the interest of the investing public,' it said.

The committee said it understood the change was perceived as dramatic and that it was brought in at too short notice.

But it stated it was 'entirely satisfied with the integrity of the consultation process relating to these proposals'.

The measure, together with a series of amendments to the listing rules, was announced about a month ago, after an almost year-long consultation.

The committee's statement came after more than 250 firms and individuals signed a letter published in local newspapers Monday to protest against the change, saying the restrictions would undermine the rights of directors and could force firms to relocate.

The signatures of the open letter included those of Hong Kong's biggest firms, including Shun Tak Holdings, headed by Macau gambling tycoon Stanley Ho, and Cheung Kong (Holdings), controlled by Li Ka-shing.