Some $171.8 billion of cross-border merger and acquisition deals between U.S. and European companies have been announced so far in 2017, the highest figure at this stage of the year for a decade as companies on both sides of the Atlantic hunt for deals to offset sluggish growth. A $14 billion tie-up between U.S.-based chemicals firm Huntsman Corp and European rival Swiss Clariant AG, announced on Monday, is the latest example of the spate of big deals between the two regions. The overall value of cross-border M&A deals between the U.S. and Europe is up 82 percent on the same period last