The German drugmaker Merck KGaA has begun legal action against Facebook after discovering what its lawyer described as the \"the apparent takeover of its Facebook page\".The webpage is being used by the German firm\'s US rival Merck & Co.Merck KGaA said that the social network \"is an important marketing device [and] the page is of great value\", adding that since its competitor was benefiting from the move \"time is of the essence.\"A Facebook spokeswoman said: \"We are looking into it.\"Merck KGaA said it had entered into an agreement with Facebook for the exclusive rights to www.facebook.com/merck in March 2010.The German firm said a number of its employees had been subsequently assigned administrative rights to the page.However, Merck KGaA said that when it had checked the site on 11 October this year it had discovered it had lost control of the page, and that content on the site now belonged to Merck & Co.The two drugmakers both stem from the same firm set up by a pharmacy owner in the German city of Darmstadt in 1668.The business was split in two after World War I as part of the reparations package imposed on Germany.Merck KGaA\'s lawyer, Robert Horowitz said he had sent a letter and a series of emails to various Facebook staff asking to discuss what had happened to the webpage.However, he said the respondents \"either did not understand the problem... [or were] intentionally giving unresponsive answers\".Mr Horowitz said that when he had requested a telephone conversation, one of Facebook\'s staff \"incredibly replied that \'no-one is available for a call at this time\'\".Merck KGaA has since filed a petition with the- Supreme Court of the State of New York.\"We took legal action versus Facebook to ask for information why a website we thought we owned isn\'t ours anymore,\" Dr Gangolf Schrimpf, a spokesman for Merck KGaA, told the BBC.\"We are just trying to learn what happened.\"However, the court filing notes that: \"Merck is considering causes of action for breach of conduct, tortious interference with contract, tortious interference with prospective business advantage, and/or conversion.\"Merck KGaA stressed that it had not taken any action against its US counterpart at this stage.Facebook was unwilling to make a comment beyond saying that it was looking into the case.Branding experts say the case reflects a growing belief that social networks can offer firms a better way of reaching their customers than through their own websites.\"Company communication departments have realised that many of the people they want to reach and influence are already on Facebook,\" said Simon Myers, from the consultancy Figtree Network.\"As corporate content becomes more tailored and engaging, social media sites such as Facebook represent a brighter future of greater customer dialogue and interaction than the current corporate website with static content and pictures of people shaking hands.\"