The Australian mining company that has lost six executives in a suspected plane crash has suspended its operations in West Africa.
Nine passengers were on the plane which was travelling from Cameroon to Congo on Saturday.
One of the men missing is Don Lewis, chief executive of Western Australia-based international mining company Sundance Resources Ltd. Another is mining magnate Ken Talbot, one of Australia's richest men.
The company's chief financial officer, Peter Canterbury, has been appointed acting chief executive officer.
Mr Canterbury says the Cameroon military is continuing its ground search after the chartered plane failed to arrive at its destination.
The executives were travelling between two mining sites.
The company has asked the Australian Stock Exchange to put its securities into a trading halt prior to the open of trade on Monday.
Mr Talbot 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 a former state government minister between 2002 and 2005.
A statement from Sundance says the chartered plane, carrying nine people, was reported missing after it failed to reach its destination, Yangadou, in the Republic of Congo, on Saturday. The plane took off from Yaounde in the Republic of Cameroon.
The executives were visiting Sundance's iron ore project in Cameroon and Congo and conducting meetings with government representatives of both countries.
A seventh person known to have been on board the missing flight was a Talbot Group investment company director.
Two other passengers have not been named and it is not clear if they are Australian.
Australian Foreign Affairs Minister Stephen Smith says the flight should have taken only about an hour and there are grave concerns for the passengers, the ABC reports.