(1)    Prohibition for domestic insurers. No domestic insurer may engage, directly or indirectly, in any business other than insurance and business reasonably incidental to its insurance business, except as specifically authorized by s. 611.26 (4), 611.26 (4) as incorporated by s. 614.24 (1), or s. 613.26 or any other provision of chs. 600 to 646; except that a domestic insurer not restricted under s. 620.03 may engage directly in any activity to the extent it is authorized to do so through a subsidiary.

   (2)   Prohibition for nondomestic insurers. No nondomestic insurer may engage in this state in any business forbidden to a domestic insurer, nor may the insurer engage in such business elsewhere if:

      (a)    The law of the insurer’s domicile forbids an insurer to engage in such business; or

      (b)    The statutes of this state specifically prohibit a nondomestic insurer to engage in such business elsewhere; or

      (c)    The commissioner orders it to cease doing such business upon finding that doing such business is not consistent with the interests of its insureds, creditors or the public in this state; or that it gives the insurer a substantial competitive advantage in relation to domestic insurers.

   (3)   Incidental business. “Incidental business” includes:

      (a)    The business of preparing and selling abstracts of title and related documents, if done by an insurer authorized to transact title insurance;

      (b)    Business that could be done through ancillary subsidiaries authorized under s. 611.26 (3), or, in the case of a nondomestic insurer, through corporations that would be so authorized if the insurer were domestic.

   (4)   Annuities. For purposes of this section, “insurance” includes “annuities”.