An assessment was completed under S. 143(3), read with S. 153A of the Act by making additions u/s. 69 of the Act. CIT (A) deleted the addition. Subsequently, AO issued a notice under S.148 seeking to reopen assessment on ground that certain amount escaped assessment towards undisclosed investment. Allowing the petition the Court held that since, in instant case, Assessing Officer sought to reopen assessment in respect of income involving a matter which was subject matter of appeal before Commissioner (Appeals), said reopening of assessment was hit by third proviso to section 147 which was not permissible in law. Accordingly the reassessment proceedings were quashed. (AY. 2011-12)