Morton Thiokol’s income increased 21% to $36.37...

Morton Thiokol’s income increased 21% to $36.37 million for the fourth quarter. The Chicago company ended the year with a 4% increase in earnings to $138 million. The specialty chemicals group posted a 49% increase in profit, the company said, and the aerospace group increased profit by 20% in the quarter. Earnings in the company’s salt group were 43% lower because of a drop in ice-control sales.