Facebook has returned Merck KGaA's page on the social network after an “administrative error” saw control of it transferred to the pharma company's US namesake.

The social network apologised for the mix up, but will not return the German Merck's vanity URL.

Instead it wants the company to come to an agreement with Merck & Co as to who should have the rights to the facebook.com/merck URL.

Last week Merck KGaA asked a New York court to force Facebook to reveal the background behind Merck & Co's apparent takeover of its corporate page.

Merck KGaA said it acquired rights to the facebook.com/merck page since March 2010 and assigned administrative rights to the page to a limited number of its employees and external service providers.

But on checking the page in October it found that not only did it not have administrative rights to the page, but that the page's content appeared to have been created by its US competitor.

In papers filed with the Supreme Court of the State of New York, Merck KGaA said: “Because Facebook is an important marketing device, the page is of great value to Merck, and its misappropriation is causing harm to Merck.”

Facebook has now stopped either side from using the page and assigned new, separate pages to each Merck.

Posting an update to its new page, Merck & Co said yesterday: “We want to assure you that our Facebook page will remain active and continue to serve as a helpful resource for information on health and well-being."

Meanwhile, the most recent update to Merck KGaA's page, seemingly returned as it was prior to its takeover by Merck & Co, dates back to June.

The original German pharmaceutical company Merck was split in two after the First World War, with each of the firms owning exclusive rights to the Merck trademark in different geographical areas.

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