Federal Reserve officials extended their efforts to boost the sluggish U.S. economy and said they were ready to do more if necessary to spur job growth, The Wall Street Journal reported today. They acted despite worries inside and outside the Fed that the central bank has already done all it can to invigorate the disappointing economic recovery. The Fed said yesterday that it would extend through the end of the year "Operation Twist," a program that aims to drive down long-term interest rates and reduce borrowing costs for businesses and households. Under the program, the Fed sells short-term securities and uses the proceeds to buy longer-term securities. Fed Chairman Ben Bernanke made clear after the policymakers' meeting that he is prepared to take further action if he doesn't see progress on bringing down unemployment, which was 8.2 percent in May. Three consecutive months of disappointing job gains and mounting worries about Europe's financial turmoil helped them reach their decision.