The banking giant Barclays has agreed to pay a $453 million fine to U.S. and British authorities for manipulating key interest rates. A British probe found Barclays conspired to manipulate the London Interbank Offered Rate, or LIBOR, which provides the basis for rates on trillions of dollars in transactions across the globe. The manipulation meant millions of borrowers paid the wrong amount on their loans. A Justice Department probe of Barclays is continuing, and other banks are expected to be implicated.