The decline was led by the Qatari index .QSI, which slipped 0.4% after a 1.1% decline in Gulf's largest lender Qatar National Bank QNBK.QA and a 0.8% decrease in Commercial Bank COMB.QA. Sept 13 (Reuters) - Major stock exchanges in the Gulf declined on Wednesday, tracking global equities ahead of release of U.S. CPI data as concerns around the Federal Reserve's rate trajectory dampened investor sentiment. Dubai's main index .DFMGI fell 0.1% as half of its stocks were in the red, including blue-chip developer Emaar Properties EMAR.DU which declined 0.7%, while Emirates Central Cooling Systems Corporation EMPOWER.DU dropped 1.1%.