Cotton futures rose the most in a single session in nearly a year on Wednesday after the US dollar fell sharply after a US Federal Reserve statement that opened the door to an interest rate hike but hinted it could take a gradual approach. The front-month May cotton contract on ICE gained 2.27 cents, or 3.8 percent, to settle at 62.48 cents after rising as high as 62.65 cents, the highest for the May contract since March 9. It was the front-month's largest single-session rise since March 25, 2014. Cotton made some early gains and they were extended sharply after the Fed statement at 2 pm EDT (1800 GMT), which prompted a drop in the US dollar against a basket of currencies. The Fed said it would be open to a rate hike, but lowered its outlook for economic growth and inflation and cut its projected interest rate path. A weaker dollar boosts greenback-traded commodities like cotton by making them less expensive to holders of other currencies. Gains in the US dollar in the past month have been a key driver of fiber's rout. Front-month cotton fell for 10 consecutive sessions between late February and mid-March as the dollar rose. Friday's late-session rise extended earlier gains, which came after prices dipped below 60 cents a lb for the first time since February 3, prompting some mill buying. "The mills definitely need to buy some more. They're not covered all the way to new crop," said Peter Egli, director of risk management at British merchant Plexus cotton Ltd. The support cotton found at those levels likely prompted speculators to cover short positions ahead of the Fed statement and a US government export sales report expected Thursday, Egli said.