State insurance, part of insurance giant Insurance Australia Group (IAG), is considering a proposal to close all except one of its 22 branches in New Zealand.

The company intends to run the Riccarton branch in Christchurch, which will meet the customer needs of earthquake-related insurance claims.

The decision could result in the loss of around 91 jobs in 21 branches.

State insurance executive general manager Craig Olsen said the proposal is based on making sure that the firm has the appropriate structure to meet the current and future needs of customers.

"Insurance is increasingly 24/7. Over the past five years fewer State customers have been visiting our branches and instead are choosing to call us or connect via our website or other online mechanisms at a time that is convenient to them," added Olsen.

"Our strategy remains to be there, across our direct insurance brands, where customers want us, when they want us, with compelling and affordable insurance products and superior support – but to achieve this we need to be efficient."

State, which employs around 1,400 people, plans to take the final decision on the proposal by mid-October this year.

The company noted that around 94% of customers choose to use website or call the firm to know about their insurance needs, or to make a claim, update their contact details or pay a bill, and that number was growing year-on-year.