This is the mirror image of the absorption combination.
Here the buyer wants to adopt the ways of the seller. The acquired company dictates the terms of the combination and effects cultural change in the lead company.
When this unusual type of combination occurs, it typically involves an acquired business unit or division absorbing the operations of a parallel unit in an acquirer. For example, REO Motor Company acquired Nuclear Consultants and, ultimately, folded its operations into the acquiree that became the modernday Nucor.