Six Australian mining executives, including billionaire magnate Ken Talbot, are on board a plane that has gone missing in the African nation of Cameroon.

The executives are from the Western Australian-based iron ore company Sundance Resources.

A statement from Sundance says the chartered plane, carrying nine people in total, was reported missing after it failed to reach its destination on Saturday.

Foreign Minister Stephen Smith says the flight should have taken about an hour in duration and he has grave concerns for the passengers.

"We are very concerned about the safety and wellbeing of six Australians and we will await the outcome of the search," he said.

"In the meantime, we will continue to give consular assistance to the company and to the family members."

Sundance says an international air and ground search which has been launched.

Billionaire Ken Talbot, a non-executive director of Sundance, was the founder of Queensland-based Macarthur Coal, but sold his stake two years ago.

He was due to face trial in Brisbane in August on 35 charges of paying secret commissions to former state government minister Gordon Nuttall between 2002 and 2005.

Others on board the plane include Sundance chairman Geoff Wedlock, managing director and CEO Don Lewis, company secretary John Carr-Gregg and non-executive directors John Jones and Craig Oliver.

A statement from Sundance says the mining executives were visiting the company's iron ore project in Cameroon and Congo.

"The families of the missing have been notified and are being supported during this deeply distressing time," it said.

Sundance says an extensive search is now underway.

"A comprehensive air and ground search will commence at first daylight local time on Sunday (approx 3.30pm AEST)."

"A Congolese aircraft will be involved in the search."

The company promised a further update as more information became available says it is coordinating with government authorities in Cameroon and Congo, as well as with Department of Foreign Affairs representatives in the region to locate the aircraft.

DFAT says the high commissioner to Abuja is in Cameroon managing the government's response on the ground.

Two other officials will also travel to Cameroon.

Sundance's chief focus is its Mbalam ore project in Cameroon which is potentially worth billions over its lifetime.

The company said it would ask the ASX to put the company's securities into a trading halt prior to the open of trade on Monday.

- ABC/AAP