With regard to two or more businesses operated by the same employer (limited to businesses other than the businesses with a definite term) and meeting the requirements specified by Order of the Ministry of Health, Labour and Welfare, if the employer applies for the grouping of the insurance relations already established in respect of the two or more businesses in a single insurance relation, in whole or in part, and obtains the approval of the Minister of Health, Labour and Welfare, the provisions of this Act apply by deeming that all workers employed for the two or more businesses so approved are employed for the one business among those businesses that is designated by the Minister of Health, Labour and Welfare. In this case, the insurance relations of the businesses other than the single business designated by the Minister of Health, Labour and Welfare become extinct.