Feb 24 (Reuters) - Minerals Technologies Inc raised its offer to buy Amcol International Corp to about $1.38 billion.
The offer of $42.50 per share represents a 7 percent discount to Amcol's Monday close.
U.S.-based Minerals Technologies and France's Imerys are both bidding for Amcol, a company that owns large reserves of bentonite, a key mineral used in construction and energy industries.
AMCOL confirmed the receipt of Minerals Technologies' revised proposal and said the board will review and consider the offer.
Minerals Technologies had offered to buy Amcol for $42 per share on Feb. 14, topping an offer of $41 per share from Imerys. Three days later Imerys said it remained committed to acquire Amcol for $41 per share.
AMCOL is incorporated in Delaware, where public companies are typically required to accept the highest offer in a deal.
The revised proposal is dependent on Minerals Technologies' receipt of sufficient financing for the transaction, Amcol said in a statement.