Chancellor Andre G. Bouchard on Tuesday let stand the bulk of a suit by the former chief executive of a technology startup accusing LifeLock Inc. and a second defendant of improperly excluding him from a settlement agreement and denying him the broad releases given to other security holders.

Bouchard, after hearing more than 90 minutes of oral argument on LifeLock’s motion to dismiss Wenceslao Casares’ complaint for declaratory judgment and reformation, said that both sides had offered reasonable readings of a key contractual provision at the heart of the case.