'New dawn' in Iran relations: Ciobo

Australia is at the dawn of a closer relationship with Iran after inking a trio of fresh agreements to forge closer ties, the trade minister says.

Steve Ciobo made the declaration after signing three separate pacts with Iranian government counterparts intended to help Australian firms in Iran.

The minister, who is leading a trade delegation of more than 20 companies to Tehran, says the aim is to position Australia as one of the first movers into the once isolated nation to capitalise on historically strong economic ties.

At its peak, Australia exported almost $1 billion worth of goods to Iran before nuclear sanctions slashed the trade to a couple of hundred million.

Companies including Woodside, WorleyParsons and Australian Water Partnership are following the minister seeking out opportunities, buoyed by the prospects in Iran's mining, oil and gas, and other industries as well as the near 80 million population.

"We are in the dawn of a new age of the relationship with Iran," Mr Ciobo told a gathering of the business leaders in Tehran on Tuesday night (local time).

Mr Ciobo admits the memoranda of understanding aren't legally binding but insists they lay the foundations for further cooperation.

"You don't often get a market of 80 million reintegrating back into the world," he told AAP.

Austrade's Tehran commissioner Lino Strangis says while it's not quite a deal, the agreements are a sign of mutual trust between the two countries.

In Iran an MoU sets the ground rules for sealing future contracts.

"They put us on a level playing field - there's a rapport and trust between the nations," he told AAP.

One of the agreements will help the Australian and Iranian banking sectors collaborate and share information.

It's designed to help pave the way for change given businesses still face considerable financial restrictions in Iran.

Another will share Australian expertise and technologies to help Iran manage scarce water resources.