Okla. Stat. tit. 79, § 208

No person engaged in trade or commerce in this state shall acquire, in any manner whatever, the stock or the whole or any part of the assets of any competing person engaged in the same or similar line of trade or commerce, in or out of this state, where, in any relevant market in this state or in any line of trade or commerce in this state, the effect of the acquisition is to substantially lessen competition or to tend to create a monopoly; provided, however, that this section shall have no application to corporations owning or holding the stock of subsidiary corporations when the ownership of stock in subsidiary corporations does not violate Section 3 of this act.