The ECB will also expand its quantitative easing programme from €60bn to €80bn a month. The scheme will now include the purchase of corporate bonds as well as government debt.
The bank has also decided to further cut the bank deposit rate. It now stands at minus 0.4%, down from minus 0.3%, meaning that banks must pay more to deposit funds with the ECB.
The package of measures, including the decision to cut the benchmark interest rate, was more radical than investors had expected.