Nifty opens above 8,100; Fed keeps key rates unchanged: Markets have extended gains for fifth straight day and have started higher after the Federal Reserve post the two-day FOMC meet kept the interest rates steady at zero and indicated it may hike interest rates in September. The Sensex has opened higher by 118.72 points at 26,944.47 and the Nifty has gained 25.90 points at 8,117.70. Asian equities rose early on Thursday after the Federal Reserve sounded more dovish than many had expected and led investors to push back their expected timing of a rate hike, while the dollar was put on the defensive on the same token. After a closely-watched two-day meeting, the Fed said the economy was likely strong enough to support an interest rate increase by the end of the year. But it lowered its expectations for 2015 economic growth because of a weak start to the year and reduced its growth and federal funds rate forecast.