Associated Cement Companies Ltd (ACC), India's second-largest cement maker, said Tuesday it is considering to merge unit Idcol Cement Ltd. with the company.  In a filing with the stock exchange, ACC said it is likely to decide on the merger at a board meeting scheduled Jan. 23.  ACC had recently bought an 86.79 per cent stake in Idcol Cement for 1.76 billion rupees ($1=INR45.42). Published under Cement News