The Government has authorised a $33.7 million injection to three Crown-guaranteed National Provident Fund schemes to help cover lower than expected returns, Finance Minister Bill English says.

The National Provident Fund offers 11 superannuation schemes to employees outside central government. The schemes have been closed to new members since 1991.

The Crown is required by legislation to top up three employer subsidised defined contribution schemes so they can meet the 4 per cent minimum return to members. The call on Government funding follows lower than expected returns as a result of the global recession.

"The payment to the three National Provident Fund schemes was signalled in Budget 2009 and an estimate included in the Budget forecasts," Mr English says.

The three National Provident Fund schemes requiring a top up are the Pension National Scheme, the Lump Sum National Scheme and the Meat Industry Scheme. The last time such a payment was required was in 2003.