(4)No loss shall be carried forward under this section for more than [four assessment years] [ Substituted by Act 18 of 2005, Section 20, for " eighth assessment years" (w.e.f. 1.4.2006).] immediately succeeding the assessment year for which the loss was first computed.[Explanation. - Where any part of the business of a company ] [Inserted by Act 41 of 1975, Section 15 (w.e.f. 1.4.1977).][(other than a company whose gross total income consists mainly of income which is chargeable under the heads "Interest on securities", "Income from house property", "Capital gains" and "Income from other sources"] [ Substituted by Act 11 of 1987, Section 74, for " other than an investment company, as defined in clause (ii) of section 109" (w.e.f. 1.4.1988).][, or a company the principal business of which is the business of banking or the granting of loans and advances) consists in the purchase and sale of shares of other companies, such company shall, for the purposes of this section, be deemed to be carrying on a speculation business to the extent to which the business consists of the purchase and sale of such shares.] [Inserted by Act 41 of 1975, Section 15 (w.e.f. 1.4.1977).]
