Surtax aggregation rule reduces surtax where combined income-tax and surtax exceed a statutory proportion of company income. The Finance Act, 1965 amends the Companies (Profits) Surtax Act, 1964 by deleting references to super-tax and substituting income-tax where specified; expanding qualifying activities to include construction as well as manufacture or production; replacing the list of specified articles; and adding a proviso that where a qualifying company's aggregate of income-tax (after adjustments) and surtax exceeds a statutory proportion of total income, the excess is deducted from surtax to determine surtax payable.