TWO long-standing food distribution companies in Glasgow are to merge. McKeans Foods, based on the Balmore Estate, and McLay Quality Foods, which has premises in Tollcross, are to create a ''one-stop shop'' for fresh and frozen foods, and dry goods. The new company will trade under the name McLay Wallace and be based at the Balmore Estate premises. No redundancies are predicted and the directors anticipate that the combination will create a company capable of a (pounds) 10m annual turnover. McLay Wallace will be jointly owned by John McLay, who will head the sales function, and Gordon Wallace, who will take charge of the production and technical disciplines.