Minnesota Mining & Manufacturing's income rose to $216 million in the quarter ended Dec. 31, compared to the year-ago quarter's $185 million. Sales advanced 12.5% to $2.37 billion. For 1987, the worldwide industrial company based in Maplewood, Minn., earned $918 million on sales of $9.42 billion, up from $779 million and $8.6 billion, respectively, in the prior year. The earnings reflect a 2-for-1 stock split, effective May 22. The company attributed the increased profit to the change in the dollar's value, worldwide volume gains and measures to reduce costs and increase productivity.