при единовременной закупке для обоих предприятий

[freelancer_06]

Данную скидку мы можем распространить и на ОАО "ААА", при единовременной закупке для обоих предприятий.
This discount can be also applied to AAA, if delivered to both companies at a time.
так нормально?

[PERPETRATOR™]

А что delivered-то? И не at a time, а at the same time.
if/when purchasing [goods] simultaneously for both companies.

[10-4]

This discount also can be applied to AAA, when AAA and BBB purchase at the same time (when AAA and BBB place a single purchase order / make a mutual purchase / etc.)

[_03]

We may consider giving a discount to AAA as well provided both firms share/jointly submit one purchase order.