Dec 20 (Reuters) - Australian shares extended gains on Wednesday, led by gold and energy stocks in broad-based buying after the country's central bank flagged signs of progress on inflation in its year-end policy meeting. Globally, investors awaited the U.S. November core personal consumption expenditure index report, due out on Dec. 22, for further clarity on the Federal Reserve's future policy decisions. Energy stocks .AXEJ rose 0.7%, in line with gains in oil prices as attacks on ships in the Red Sea disrupted maritime trade and forced more companies to reroute vessels.