Spanish energy giant Iberdrola has moved to break the delay in acceptances of its takeover bid for Infigen Energy, offering an extra 3¢ a share if it gets at least another 13 per cent of the shares by the end of July.

The conditional 3.4 per cent increase takes the all-cash takeover offer from 89¢ a share to 92¢, valuing the country's largest listed renewable energy player at about $893 million.