16.1. If the amount paid to the spouse comes from the entitlement to a pension referred to in subparagraph 3.1 of the first paragraph of section 3 or to a pension credit payable at the date on which that pension is payable, the benefits of the employee or former employee shall be established in accordance with the Act and his pension or pension credit shall be reduced, from the date on which it becomes payable or from the date of payment, as the case may be, by the amount of pension or pension credit that would be obtained on the basis of the sums awarded to the spouse at the date of assessment.