ACC said today it will shortly revise a number of Substantial Security Holder (SSH) filings on listed companies taking account of the corporation's holdings combined with the personal stakes of its investment officers.

The corporation, one of the biggest investors in the country with over $6 billion in its portfolio, said it had had recent legal advice on the meaning on the Securities Markets Act, which governs the requirements for substantial security holder notices.

"This legal advice indicates that investment staff would be deemed to have a relevant interest in ACC's shares if there is a likelihood that those staff members may sometimes have a significant role in decisions that ACC makes to buy or sell those shares, or to exercise voting rights with respect to those shares," ACC said in a statement.

The notices will show that some of ACC's investment staff have a non-beneficial relevant interest in some, or all, of the shares that ACC holds in the listed companies.

ACC said its investment staff had been made aware of their legal obligation to file SSH notices where their personal shareholdings plus those shares held by ACC over which they have some degree of control represent a combined 5 per cent or more of a company's voting securities.

Where there was uncertainty over whether investment staff do have a "relevant interest',' the corporation said it had leaned towards disclosure.

"To avoid any misinterpretation, ACC wishes to emphasise that the interest that investment staff are deemed to have in ACC's shares is entirely non-beneficial, and that the degree of control that investment staff have over these shares is similar to the control that the staff of other fund management companies have with respect to the shares which they manage."

ACC said it believed many other fund management staff were in a similar position to ACC staff with respect to personal shareholdings.

ACC investment staff are required to seek pre-approval for personal share transactions and to disclose these transactions when they have been undertaken.

It had a code of conduct to prevent investment staff from profiting from ACC's market activity.

ACC's chairman and chief executive are required to put their investments into a "blind trust", similar to those used by politicians, but a spokesman said that in respect to its investment executives "we expect managers of that calibre to be active managers in their own right".

"ACC believes it has appropriate controls in this area."

He said that because of the scale and complexity of ACC'S portfolio a blind trust manager would be swamped by the quantity of transactions.

John Norling a spokesman for fund manager Alliance Capital Management said his organisation was unaware of the requirement to combine the fund's holdings with those of its investment staff. Alliance had stringent restrictions on the trading activities of its staff, which had to be cleared through the New York head office.

The effect of the requirements meant it impractical for investment officers to trade significantly on their own behalf.