A forecast 15-20% rise in offshore energy insurance rates has failed to materialise, and October renewals should stay generally flat, according to Aon.

It says insurers are still trying to exact rate rises from companies with large and/or complex risks in the wake of expensive hurricanes Katrina (2005) and Ike (last year), but there are still good deals to be made in a competitive market for medium-sized risks.

Keeping a lid on rates in the middle market has been the absence of “market-changing” losses, relatively stable capacity and increasing economic optimism.

Aon says London-based insurers are offering increasingly competitive rates as more localised business emerges.