In what is expected to become a bidding war, a management-led National Gypsum group raised its offer for the company, apparently topping a bid made last week by Wickes Cos. The new offer calls for the management group to pay $46 in cash and $28 in notes for each of the company's 22.8 million shares. That would give the new offer a face value of $1.69 billion. If the notes are discounted by investors at the same rate as in management's previous offer, the value would be reduced to $1.42 billion, or about $62.28 per share. That would still beat Wickes' 11th-hour all-cash offer of $54 per share, or $1.23 billion, made last Tuesday.