plan which chairman, president and chief executive officer Brian Duperreault said will protect the company against a hostile takeover.

"The purpose of the shareholder rights plan is to protect the interests of our shareholders by encouraging potential buyers to negotiate directly with the board and by providing the board with the leverage to maximise shareholder value,'' he stated in a press release.

Mr. Duperreault said the adoption of the plan was not in response to any known effort to acquire control of ACE. The shareholder rights plan makes it more expensive for a company to gain control of ACE.

Under the plan each shareholder of record on June 1 will receive a distribution of one right for each ordinary share of the company. Initially the rights will be recognisable by the company's ordinary share certificates.

The rights will not be traded separately from the ordinary shares and will not be exercisable.

The rights become exercisable only if an interest acquires or announces a tender offer that will result in ownership of 15 percent or more of the company's ordinary shares. The right will then enable the holder to buy one-thousandth of a share of the company's Series A preference stock at an exercise price of $150, subject to adjustment.

Once the 15 percent or more of the company's ordinary shares are acquired, the holders of the rights -- other than the acquiring person or group -- will be entitled to buy ordinary shares at half-price. In the event of a merger or other acquisition of the company, the rights will allow holders to buy shares of common stock in the acquiring entity at half price.

ACE has the option of redeeming the rights for one cent a right, subject to adjustment, at any time before the acquisition attempt. The rights expire June 1, 2009.