Putnam Investments, the US mutual fund group, is closing 11 retail funds worth a combined $5.2bn (€5.8bn), in an effort simplify its product range and stem losses.

Putnam is to merge 10 of its retail funds into larger funds and will liquidate the small Putnam Preferred Income Fund. Once approved, the mergers would reduce Putnam's open-end retail fund offerings by 17% - but it will still operate 55 funds.