(4)Any Producer Company, either by itself or together with its subsidiaries, may invest, by way of subscription, purchase or otherwise, shares in any other company, other than a Producer Company, specified under sub-section (2), or subscription of capital under sub-section (3), for an amount not exceeding thirty per cent of the aggregate of its paid-up capital and free reserves:Provided that a Producer Company may, by special resolution passed in its general meeting and with prior approval of the Central Government, invest in excess of the limits specified in this section.