Fri Jul 6, 2012 12:58pm EDT FRANKFURT (Reuters) - Germany's markets regulator has launched a special probe into Deutsche Bank over suspected manipulation of interbank lending rates, joining authorities around the globe investigating the world's largest banks, two people familiar with the matter said on Friday. Investigators in the United States, Europe and Japan are examining more than a dozen big banks over suspected rigging of the London Interbank Offered Rate (Libor). Britain's Barclays has so far been the only bank to admit wrongdoing, agreeing last week to pay a fine of more than $450 million. The Libor rates, compiled from estimates by large banks of how much they believe they have to pay to borrow from each other, are used to determine interest rates on trillions of dollars worth of contracts around the world. The two sources said Germany's BaFin regulator was now probing Deutsche Bank with a "special investigation," a process initiated by the regulator which is more severe than a routine investigation initiated by a third party. The results were expected to emerge in mid July, one of the sources said. Deutsche Bank said earlier this year it was cooperating with authorities investigating manipulation of Libor, the only German bank to make such a disclosure so far. The bank declined to comment on Friday but referred to its quarterly report, which said it has received subpoenas and requests for information from U.S. and European authorities in connection with setting interbank rates. BaFin declined to comment specifically on whether it was probing Deutsche Bank but said it was in looking into suspected manipulation of Libor rates by banks. Deutsche Bank has disclosed that it is cooperating with the U.S. Department of Justice, the U.S. Securities and Exchange Commission, the Commodity Futures Trading Commission, and the European Commission on Libor. These inquiries relate to periods between 2005 and 2011. As the credit crisis intensified between 2006 and 2008, allegations started mounting that Libor no longer reflected the real cost banks were paying for funds. Authorities have been examining whether traders tried to influence the rate to profit on bets on the direction it would go. The daily Libor poll asks banks at what rate they think they will be able to borrow money from each other in 10 major currencies and for 15 borrowing periods ranging from overnight loans to 12 months. The rates submitted by banks are compiled by Thomson Reuters, parent company of Reuters, on behalf of the British Bankers' Association.