(1)Notwithstanding anything to the contrary contained in section 139, where any person has entered into an agreement and prior to the date of entering into the agreement, any return of income has been furnished under the provisions of section 139 for any assessment year relevant to a previous year to which such agreement applies, such person shall furnish, within a period of three months from the end of the month in which the said agreement was entered into, a modified return in accordance with and limited to the agreement.
