Stamford, Connecticut-based Gartner Group Inc, with one of the tiny handful of blue chip names in computer industry research, is buying another. It is to pay Dun & Bradstreet Corp $75m in cash and shares for Dataquest Inc, San Jose in a deal that actually in?creases Dun’s stake in Gartner – it currently owns just over 50% of Gartner. Dataquest will gain from Gartner’s extensive global distribution network and Gartner Group will benefit from Dataquest’s solid presence in Europe, Japan and the Asia-Pacific region, the companies declared.