British oil and gas supplier Centrica announced Thursday that its profits and revenues tumbled in the first half on sliding prices -- an update that sent its share price crashing.

Profit after tax slumped 68 percent to £1.3 billion ($1.7 billion) as revenue decreased more than one third to £10.1 billion, Centrica said in a statement.

Its share price shed nearly eight percent in reaction.

"Our core businesses continued to deliver in line with our expectations in the first half of 2024, against the backdrop of more normalised market conditions," Centrica chief executive Chris O'Shea said in the earnings statement.

Gas, along with oil and electricity prices, have fallen heavily since soaring in the wake of Ukraine's invasion by major energy producer Russia in early 2022.

Energy bills remain elevated, however, prolonging a cost-of-living crisis for millions of Britons.

"Centrica's wholesale operation meant it was a direct beneficiary of an increase in oil, gas and electricity prices," noted AJ Bell investment analyst Dan Coatsworth.

Falling profits "as prices come down shouldn't come as a major surprise", he added.

Around 1200 GMT, shares in Centrica were down 7.6 percent at 132.15 pence on London's top-tier FTSE 100 index, which was 0.6-percent lower overall.