(1) It is unlawful for any person engaged in trade or commerce to acquire, directly or indirectly, the whole or any part of the stock or other share capital, or to acquire the whole or any part of the assets, of another person engaged in trade or commerce where the effect of such acquisition may be to substantially lessen competition or may tend to create a monopoly.

(2) Nothing in this section shall prohibit any person from acquiring stock of another person solely for investment purposes, so long as such acquisition of stock is not used, by voting or otherwise, to bring about, or to attempt to bring about, the substantial lessening of competition; nor shall anything in this section prohibit any person from causing the formation of subsidiary corporations or from owning and holding all or any part of the stock of such subsidiary corporation.

(3) The attorney general shall not challenge any merger or acquisition under the provisions of this section which has been reviewed by any federal department, agency, or commission under section 7A of the federal "Clayton Act" and for which all applicable waiting periods have expired or have been terminated without a challenge to such merger or acquisition by that department, agency, or commission.

(4) The attorney general shall not challenge the merger or acquisition of any bank or bank holding company by or with any other bank or bank holding company that is subject to the provisions of any of the federal banking laws, except as specifically provided in those laws.