By Philipp Halstrick FRANKFURT, Jan 11 (Reuters) - Germany's financial regulatorwill question Deutsche Bank AG's leaders in comingweeks as part of a probe into the manipulation of the Liborrate, two sources familiar with the investigation said. Deutsche Bank Chairman Paul Achleitner and Co-ChiefExecutives Anshu Jain and Juergen Fitschen are among those dueto be questioned by Bafin, the sources said on Friday. "The questioning of top managers is standard procedure in aspecial probe," one of the sources said. Bafin has been investigating for months what role Germany'sflagship lender may have played in an international scandalinvolving how the London Interbank Offered Rate (Libor) was set. Libor, compiled from estimates by large banks of how muchthey expect to pay to borrow from each other, is used as areference to set interest rates on trillions of dollars worth ofcontracts around the world. Deutsche Bank has said it is cooperating with authorities inthe investigation. An internal enquiry by the lender found nocurrent or former management board members were inappropriatelyinvolved. Before becoming Co-CEO, Jain was in charge of the investmentbanking division, where Libor rates were set. Deutsche declined comment. Sources familiar with the matter had told Reuters onThursday that Bafin expects to complete its investigation by theend of March. Bafin is focusing on potential structural weaknesses inDeutsche's internal controls, as well as possible wrongdoing byindividual Libor traders. POSSIBLE FINE Financial daily Handelsblatt on Friday cited sourcesfamiliar with the investigation as saying the bank had for toolong underestimated the risk of Libor manipulation, and shouldhave started its internal probe and adjusted processes muchearlier. Deutsche Bank could face a fine if that view is confirmed,the paper said. Bafin declined to comment. Regulators in Europe, Japan and the United States have beenexamining more than a dozen big banks over suspected rigging ofLibor. British lender Barclays agreed to pay a fine ofmore than $450 million, and Swiss bank UBS agreed topay $1.5 billion to regulators over its submissions of interbankrates. Deutsche Bank has viewed any manipulation to be the work ofindividuals who have already been suspended by the bank, banksources have told Reuters. As the credit crisis intensified from 2006 through 2008,suspicions grew that Libor no longer reflected the true costbanks were paying for funds. Authorities have been examiningwhether traders tried to influence the rate to benefit their ownpositions. The daily Libor poll asks banks at what rate they think theywill be able to borrow money from each other in 10 majorcurrencies and for 15 borrowing periods ranging from overnightloans to 12 months. Thomson Reuters, parent company of Reuters, has beencalculating and distributing Libor rates for Libor's sponsor,the British Bankers' Association, since 2005.