The board of directors of Thermax, which met today, has approved a proposal for sub-division of equity shares in the ratio of 1:5 i.e one equity share of Rs 10 each would be split into five equity shares of Rs 2 each.This was announced in a release issued by the company to the BSE today.The stock declined nearly 2% (Rs 22) to Rs 1,139 on the BSE today.