Shares in Elan climbed today after news that the company had reached an agreement to resolve a dispute between Elan and its US partner Biogen Idec.
By 12.30pm, the stock was up 1.4 per cent to €5.30 on the Irish market.
However, Johnson & Johnson said it would cut the amount it will pay for its 18.4 per cent stake in Elan by $115 million to $885 million.
Goodbody stockbrokers said investors would be comforted by the fact that there will be no further dilution in Elan's stake of the API programme and no loss of Tysabri rights.
J&J agreed in July to acquire an 18.4 per cent stake in Elan for $1 billion, or $9.32 a share, and it agreed to pay $500 million for a majority stake in Elan's portfolio of experimental Alzheimer's drugs.
The premium, at roughly 33 per cent, was not spectacular compared with other premiums paid in the biotech sector, which can reach 40 to 50 per cent. Elan is weighed down by more than $1 billion in debt.
However, Elan had also given J&J an option to acquire a 50 per cent share of multiple sclerosis Tysabri should Biogen, with which it sells the drug in a 50-50 partnership, be acquired.
Under their agreement, Biogen and Elan have the exclusive right to acquire full ownership of Tysabri if the other is acquired. The right cannot be transferred or assigned to a third party.
When news of the agreement came out, Biogen filed suit, claiming breach of contract. A US judge agreed, saying Elan had transferred control of the right to J&J.
A spokesman for New Brunswick, New Jersey-based J&J said, "we have nothing to add to the information about Johnson & Johnson in the press release issued by Elan."