(Adds share price reaction and outlook) Aug 3 (Reuters) -...

(Adds share price reaction and outlook)

Aug 3 (Reuters) - Australian insurer Suncorp Group (SUN) reported a 5.1 percent rise in annual cash profit on Thursday, helped by growth in its Australian insurance business and lower claim costs, but came in just below analyst expectations.

Australia's second-largest insurer by market share said its cash profit for the year to June 30 rose to A$1.15 billion ($916 million) from A$1.09 billion a year ago.

A survey of eight analysts had expected cash earnings of A$1.16 billion, according to Thomson Reuters I/B/E/S.

The company's shares fell 5 percent in early trading on Thursday.

Insurers in Australia had a difficult first half of 2017 as bad weather pushed up natural disaster claims.

Suncorp said it planned to invest about A$100 million over the course of 2018 to attract more customers, a move which could adversely impact its cash earnings.

It bought a new reinsurance cover for natural disasters in 2018 to gird against higher natural hazard costs seen in recent years.

The insurer's net profit after tax from its New Zealand business more than halved over the year, impacted by the Kaikoura earthquake and additional claims from the Canterbury earthquake.

Suncorp also said it expected its dividend payout for the year to June 2018 will be above 80 percent of cash earnings. ($1 = 1.2561 Australian dollars)