WASHINGTON (MarketWatch) -- Federal Reserve officials have decided to end its asset purchase program in October if the economy stays on track, according to the minutes of the June meeting released Wednesday. According to the plan, the Fed will make a $15 billion final reduction at its October meeting, after trimming it by $10 billion at each meeting up to that point. After a discussion of its exit plan, Fed officials generally agreed to keep reinvesting the proceeds of securities that mature on its balance sheet until after it had hiked interest rates. Fed officials also agreed that the rate of interest on excess reserves would plan a "central role" in moving rates higher when the time comes. It will have an overnight reverse-repo facility with an interest rate set below the IOER rate. The spread would be "near of above the current level of 20 basis points and give the Fed adequate control over interest rates. Fed officials said they would release a more detailed exit plan later this year.