Investment manager AMP Capital Investors (AMP) has made a series of changes to the $2.5 billion bond portfolio in its Future Directions Fund.

AMP has dropped an $875 million mandate with Wellington Management, added two new managers and shifted its bond exposures in order to increase the portfolio's active risk.

The added managers are Putnam Investments and United Kingdom-based manager Mondrian.

They will share a $1.25 billion mandate or 50 per cent of the total portfolio.

"Putnam find alpha from sector rotation and are early innovators of new securities," Future Directions Fund investment director Sean Henaghan said.

"Mondrian is a value, long-term investor that forecasts two-year inflation numbers to drive yields. It's a basic process but it works and it has been a strong performer in negative markets."

AMP's exposure to French manager Crédit Agricole, which runs a global government bond portfolio, has been dropped from 35 per cent of the portfolio, or $875 million, to 25 per cent of the portfolio, or $625 million.

Goldman Sachs and Hyperion are already managers within the bond portfolio. Hyperion, which runs an asset-backed mortgage fund for AMP, has had its allocation reduced from $375 million to $250 million.

Goldman Sachs, which runs a credit fund, retains 15 per cent or $375 million of the portfolio.

Explaining the changes, Henaghan said they were driven by a desire to diversify the portfolio while ramping up the active risk.

"With the old weightings we found that about 65 per cent of the risk in the portfolio was attributed to Goldman Sachs, Hyperion and Wellington, which were all finding it difficult to get their tracking error up," he said.

"We wanted to beef up our active risk in the multi-sector portfolio and reduce our allocation to the single-sector government bonds."