Warburg Pincus, a New York-based private equity group, is pushing ahead with plans to float ProStrakan, the Scottish biotechnology company, despite having to cut the offer price by approximately 25%.

Warburg Pincus, and other backers including 3i, had hoped the sale would value ProStrakan at about £220m (€319m), but a valuation of closer to £160m looks more likely if the listing goes ahead.