Elan has confirmed that it is being sued for patent infringement by US healthcare group, Allergan.

The suit, which was filed in December, relates to Elan's Myobloc product and its use in the treatment of cervical dystonia.

Analysts said such cases were common in the industry and that the product was small in a group context. Sales of Myobloc last year are believed to have been around $15 million (€14.21 million).

However, they said the case could impact on Elan's ability to dispose of Myobloc in the near future if it chooses to sell it as part of its asset disposal programme.

Merrion Stockbrokers said it had assigned a disposal value of €180 million for Myobloc.