The downgrade came on the heels of the announcement that Keycorp, which has $67 billion in assets, would acquire AutoFinance Group Inc. for $325 million, or about 3.8-times book value. In a presentation prepared for delivery at the analysts symposium Tuesday afternoon, Keycorp executives outlined a five year strategy emphasizing community banking, private banking, national consumer finance and corporate banking. The officials said the bank is testing ways to customize branch offices to the targeted customer segments, automating routine transactions. They spoke of a period of investment in 1995 and the first half of 1996 that would pay off in the second half of 1996 in double digit earning growth. Also on Tuesday, Thomas H. Hanley of CS First Boston added Midlantic Corp. to his coverage list with a buy rating, predicting the Edison, N.J. banking company would be bought within a year. Stephen Kleege in New York contributed to this article.