Gartner Group Inc is complementing its strong IBM and East Coast research expertise with the acquisition of Cupertino, California-based InfoCorp, which will expand its coverage of mini- and personal computer, and peripherals markets, as well as giving it a strong presence on the West Coast. InfoCorp was formed in 1982 by three analysts from Dataquest and had turnover of about $3m in 1986 to add to the $22m or so done by Gartner. Terms of the acquisition were not given but they involve a cash payment at closing and performance-related payments for several further years.