* Fed signals it could still tighten by year end
* BOJ adopts target for long-term interest rates
* Indexes up: Dow 0.42 pct, S&P 0.53 pct, Nasdaq 0.45 pct (Updates with Fed decision)
By Lewis Krauskopf
Sept 21 (Reuters) - Wall Street gained on Wednesday after the U.S. Federal Reserve's decision to leave interest rates unchanged.
The central bank strongly signaled it could still tighten monetary policy by the end of this year as the labor market improved further. The Fed said U.S. economic activity had picked up and job gains were "solid" in recent months.
Traders generally had not expected the Fed to raise rates, with bets before the meeting of only an 18 percent chance of a hike, according to the CME FedWatch website.
"I don't think anybody is too surprised," said Alan Rechtschaffen, portfolio manager at UBS in New York. "There was some noise that the Fed might surprise the markets, but this Fed doesn't really do that."
The Dow Jones industrial average rose 76.53 points, or 0.42 percent, to 18,206.49, the S&P 500 gained 11.36 points, or 0.53 percent, to 2,151.12 and the Nasdaq Composite added 23.79 points, or 0.45 percent, to 5,265.14.
After the Fed decision, 10 of 11 major S&P sectors were in positive territory. Energy shares were the best performing sector, up 1.7 percent.
Earlier on Wednesday, global markets reacted to the Bank of Japan's abrupt shift to targeting interest rates on government bonds to achieve its elusive inflation target. Global stock indexes rose and the dollar fell to its lowest against the yen in nearly a month. (Additional reporting by Chuck Mikolajczak in New York and Yashaswini Swamynathan in Bengaluru; Editing by Don Sebastian and Nick Zieminski)