The Bank of England on Thursday announced to further inject 50 billion pounds (about 78 billion U.S. dollars) over the next four months via its quantitative easing (QE) program to try and boost demand.

Market has been keenly awaiting the QE expansion since last month's Monetary Policy Committee meeting, when four of the nine members voted to increase QE.

QE is a stimulus scheme of the central bank injecting liquidity into the economy via purchasing bonds. The latest increase takes Britain's QE size to 375 billion pounds.

Meanwhile, the Bank said it would leave the benchmark interest rate unchanged at 0.5 percent, a record low having been kept for over three years.

Britain dropped back into recession after its GDP contracted by 0.3 percent for two consecutive quarters. The Bank said the country's economy had "barely grown for a year and a half."

Last month, the Bank announced two new stimulus measures. One is to provide banks with access to tens of billions of pounds of cheap credit on condition that they lend this on to businesses. The other one is to povide banks with access to cash if they encounter short-term funding difficulties.

The London stock market surged after the additional QE was announced at midday.