May Department Stores Co, owner of Lord & Taylor and Filene's department store chains, today posted a 36 per cent plunge in first quarter net profit to $70 million after being hit by charges for combining some operations. The operator of 436 department stores said its results included a $40m pre-tax charge for the merger of the Kaufmann's division with Filene in the Northeast, and of Meier & Frank with Robinsons-May in the West and Northwest regions.