The UK's National Association of Pension Funds (NAPF) has sent a letter to members asking for evidence in support of its call to pension fund regulators to ease minimum funding requirement (MFR) investment restrictions.

NAPF's move follows the events of September 11, which led to a sharp fall in the value of equities, and a fall in bond yields, which in turn caused a significant decline in MFR liability cover for most pension schemes.