Johnson & Johnson is acquiring Micrus Endovascular Corp, which specialises in devices for stroke and brain aneurysms.

The healthcare giant will pay $23.40 per share, representing a 5.5% premium to Micrus' closing price last Friday and valuing the deal at around $480 million. The transaction requires shareholder approval and is expected to close during the second half of the year.

Micrus, which is based in San Jose, California is “solely focused on the neurointerventional market”, J&J noted, and develops new technologies to improve the treatment of ischemic stroke and aneurysms. Revenues were $91.1 million in the fiscal year ended March 31.

Micrus will combine with J&J’s neuro device business Codman & Shurtleff and come under the umbrella of the DePuy family of companies. The latter’s chairman, Michael Mahoney, said the merger represents “a significant step forward in the delivery of technologies for the prevention and treatment of stroke".

The deal was announced hours before Covidien completed its $2.6 billion acquisition of ev3 Corp, a competitor to Micrus.