771R4. Subject to the special provisions in Chapters III and IV, where, in a taxation year, a corporation has an establishment in Québec and an establishment in another jurisdiction, the proportion that the business carried on in Québec is of the aggregate of the business carried on in Québec and elsewhere, is one-half of the aggregate of(a) the proportion that its gross revenue for the year reasonably attributable to the establishment in Québec is of its total gross revenue for the year; and
(b) the proportion that the salaries and wages paid by the corporation in the year to the employees of the establishment in Québec is of the total salaries and wages paid in the year by the corporation.