QBE Group has successfully completed its acquisition of specialist US crop insurer NAU Country Insurance.

Initially announced on April 16, the $US565 million ($668 million) deal hands QBE a business that last year earned $US976 million ($1.15 billion) in gross written premium, including control of about 11% of the US multi-peril insurance market.

QBE announced completion of the deal on Friday following approval from US regulators.