Washington (AFP) – The dominant US services sector contracted for the first time in more than two years in December, survey data showed on Friday, as business activity slumped. The Institute for Supply Management’s services index dipped below a key 50-percent threshold, indicating a contraction and surprising economists. The sector accounts for two-thirds of the world’s largest economy and has held up in spite of a forceful campaign by the Federal Reserve to cool demand and rein in surging inflation — but the higher interest rates now appear to be biting. The ISM services index “ended a 30-mo…