LONDON, Nov 8 (Reuters) - Alleged manipulation of the Libor benchmark interest rate can be included in two court cases involving Barclays BARC.L and Deutsche Bank DBKGn.DE , a British judge said in what could be seen as a landmark ruling on Friday. The decision, handed down in the UK Court of Appeal, is seen as potentially setting a precedent and could open the door to many more cases being brought against the industry by companies citing the manipulation of the key lending benchmark. Successful court cases could expose banks to compensation claims worth billions of pounds from borrowers. In previous legal rulings judges have stopped short of saying Libor is relevant to all claims against banks but said it could be used in cases where contracts have been linked specifically to the benchmark. Deutsche Bank said it was disappointed by the Judge's decision to include some Libor matters in its case against Indian property company Unitech. The bank said it intended to launch an appeal. Echoing the German bank's disappointment, Barclays said the allegations of mis-selling Libor-linked interest rate hedging products to client Graisley were without foundation. "With or without the Libor claims, the allegations of mis-selling have no merit," the British bank said in a statement. The rulings followed a 3-day hearing at the Court of Appeal at London's Royal Court of Justice last month. (Reporting by Steve Slater, additional reporting by Clare Hutchison, writing by Sinead Cruise, editing by Chris Vellacott) ((sinead.cruise@thomsonreuters.com; +44 207 542 5154; Reuters Messaging: sinead.cruise.thomsonreuters.com@reuters.net)) Keywords: LIBOR GUARDIAN/