LONDON — A London court has dismissed charges against Barclays tied to the bank’s 2008 efforts to raise a $15 billion lifeline from Qatar and other investors, a legal victory for the British lender as it tries to turn its businesses around.

The decision is a blow to Britain’s regulators, who have pursued the case for years. The charges were the first in the country against a bank for actions during the global financial crisis.

And the news is likely to be well received by Barclays, which has sought to move past a welter of scandals and underperforming operations. The firm paid $2 billion to settle American charges of fraudulently misrepresenting securities tied to home mortgages, as well as a separate settlement over charges tied to allegations that it manipulated the interest rate known as Libor.

And this month, its American chief executive, James E. Staley, received a relatively small fine for trying to uncover a whistle-blower.