The Assessing officer issued two notices under section 148, containing different reasons to believe, both of which were approved by the Commissioner on the same day. The first notice diverted the jurisdiction of the Assessing officer from initiating another reassessment proceeding. At the time of the second notice, the AO had already initiated the reassessment proceedings through the first notice. Once the reassessment proceedings are pending, the entire assessment is open and not confined to the reasons recorded by the AO for assuming jurisdiction. Instead, it should have issued both the reasons in the first reopening notice and not taken recourse to initiate piecemeal reassessment proceedings. As the AO is precluded from simultaneously embarking upon two sets of proceedings u/s. 147 of the Act, the second notice and the reassessment proceedings based on it are quashed. (AY. 2009-10)