LONDON — The Bank of England trimmed its economic growth forecast for 2019 and 2020 on Thursday, and said British economic data had become “volatile” as the deadline for leaving the European Union approached.

Still, the bank decided to keep its benchmark interest rate at 0.75 percent. The British pound, which had slid just before the midday announcement, ticked up slightly in afternoon trading. In a statement, the central bank said that “intensifying Brexit-related uncertainties on business investment and weaker global growth” were hurting the British economy.

“The level of uncertainty that is affecting businesses has continued to increase,” Mark Carney, the bank’s governor, said later in a news conference, “and it is also clear that there has been a substantial shortfall in investment as a consequence of that.”