Investment manager AMP Capital Investors has made more than five investments in alternative assets in the past 18 months.

It has funded investment managers Acorn Capital, Nephila Capital and JPMorgan and made investments in three private equity funds.

Each investment was worth about $25 million to $30 million, AMP Capital Investors investment director Sean Henaghan said.

Henaghan heads the international and Future Directions funds for AMP Capital's multi-manager business.

He said he plans to build the firm's alternative asset portfolio in the next 12-18 months.

"The decision we made a couple of years ago not to get into illiquid investments really hurt our portfolio," he said.

"But as I said to our clients, you don't make investment decisions over a 12-month horizon. These really take three years and that discipline from last year is really benefiting us this year as we now have the money to invest in these things."

The Acorn Capital fund will invest in unlisted micro-cap stocks, Nephila will manage an insurance-linked securities mandate and JPMorgan will manage an India/China infrastructure fund.

The private equity investments give AMP Capital exposure to the finance and energy sectors, pharmaceutical royalties and mid- to large-cap companies.

"We decided to steer away from [private equity] managers with big legacy portfolios. Our view is that these funds will spend a lot of time managing their existing investments. We would rather find managers that have the time to look at opportunities," Henaghan said.

The business would look at hiring more people, particularly in the area of alternative assets, he said.

"Obviously we will need to build our expertise in alternatives as these investments take time," he said.

The investment manager is currently advised by Mercer Implemented Consulting and US-based consultant StepStone Group.