The Finance Ministry has extended the income tax exemption for 46 lakh subscribers of over 2,700 private Provident Fund Trusts till March 31st, 2013. Subscribers of these private PF trusts were facing the threat of their retirement funds coming under tax net as Budget 2012-13 was silent on this issue. A Finance Ministry official said, the amendment has been incorporated in the Finance Bill which was approved by the Lok Sabha on Tuesday.In 2006, the then Finance Minister P Chidambaram had made it mandatory for all private PF trusts to seek exemption certificates from the Labour Ministry within a year for enjoying the tax benefits.