Irish biotech group Elan yesterday sold an 18 per cent stake in US drug firm Alkermes, three-quarters of its holding, for $381 million, net of underwriting costs.

Elan received a 25 per cent stake in Alkermes plus €500 million last year in exchange for its Athlone-based drug delivery business.

At the time, the shares of the company were valued at $14.47.

Yesterday’s placing at a price of $16.50 deliver a 14 per cent gain over the period.

Elan had agreed not to sell the shares before the end of a six-month month lock-up period, although Alkermes is understood to have waived that restriction to facilitate yesterday’s placing.

Elan, which continues to own 7.75 million shares, around 6 per cent of Alkermes, said these proceeds of the placing “further strengthen Elan’s cash balances and capital structure”.

On the basis of yesterday’s placing, the outstanding holding in Alkermes is worth just under $130 million. – (Additional reporting: Reuters)