The sale would allow Swiss firm Holcim, the worlds number two cement group, to consolidate its Philippine interests. Holcim has stakes in Union Cement and holds indirect and direct stakes in Alsons.
Alsons board also agreed to the plan to delist the firms shares from the Philippine Stock Exchange after the acquisition, the company said in a statement to the exchange.
Alsons said Union Cement will buy an 88 percent stake of its outstanding capital from Alsons major shareholder, Cemco Holdings Inc, via a share swap, with Union later opening a tender offer for all the remaining Alsons shares.
Holcim owns a 40-percent stake in Cemco and directly owns about 3.54 percent in Alsons.
"Based on the review of the Union Cement offer, the board agreed that...the transaction will benefit both Alsons and Union Cement," Alsons said in its disclosure.
"The board agreed to communicate their recommendation for the shareholders of the corporation to accept the offer of Union Cement."
Alsons said some officers of Union Cement have already been appointed to senior positions in the firm preparatory to the closing of the sale. Holcim said in July the transaction should be closed in October.