Last year the GSF hired Australian consultant Chant West to investigate implemented consulting solutions for the $2 billion which it was about to transition from passive to active management.

It is understood Mercer and Russell were both contenders for the GSF implemented consulting contract.

Langford said while it was a "line-ball decision" the costs of keeping the international equities management in-house were about the same as outsourcing to an implemented consultant.

"We've given implemented consulting serious thought," he said.

After the investment tax changes last year that removed favourable treatment for passive equity investment strategies, the GSF decided to move approximately $2 billion in passive international equities - that was shared between AMP and Axa - to an active strategy.

From October 1 last year the GSF has been gradually transitioning the international equities to a number of managers - seven global share managers have already been appointed with at least one more expected to be named soon.

The seven managers appointed so far are: Altrinsic Global Advisers; Arrowstreet; Barclays Global Investors Australia (enhanced index); Marathon; PanAgora Asset Management; State Street Global Advisors (enhanced index); and, T Rowe Price.

"We had about 12-15 RFPs out there during the process," Langford said.

He also said the GSF has reappointed JP Morgan as custodian after a review conducted by Mercer last year.

The $4 billion GSF is a defined benefit fund which partially funds New Zealand's public sector retirement liabilities.