By DAVID McHUGHFRANKFURT, Germany (AP) â¿¿ The European Central Bank and the Bank of England on Thursday underlined their determination to keep interest rates low in an attempt to reassure markets unsettled by the possible end of the U.S. Federal Reserve's bond-buying program. Abandoning a longtime practice of saying it "never precommits" on interest rate decisions, the ECB said it would keep its benchmark interest rate the same or lower "for an extended period of time." The statement followed a meeting of the bank's rate council which left the refinancing rate for the 17 European Union countries that use the euro unchanged at 0.5 percent. Draghi said the decision followed "an extensive discussion" of a potential rate cut. Instead of a cut, the bank offered what is called "forward guidance". The practice â¿¿ already used by the U.S. Federal Reserve â¿¿ is designed to give markets clarity about central bank's future course of action in order to influence and reassure markets. The Bank of England did something similar at its monthly meeting Thursday. Under new governor Mark Carney, the bank issued a statement saying that expectation of a rate rise "was not warranted". The Bank also kept its main interest rate at 0.5 percent. Markets reacted dramatically to the two banks' statements. In London, the FTSE 100 index of leading shares closed up 3.1 percent, while Germany's DAX stock index ended Thursday 2.11 percent higher. Both the euro and pound fell on the two banks' actions as investors moved their investments to currencies with a higher return. The goal of the ECB and the Bank of England was to keep bond market interest rates from rising and hurting economic growth through higher borrowing costs. Market rates have crept up since the Fed signaled last month it could begin phasing out its bond-buying program this year.