A 25-year-old Angolan passenger survived the crash, which took place around 10am (0900 GMT) as the plane was preparing to land at Lubango, in the southwestern province of Huila, the Angolan charter company Sociedade de Aviacao Ligeira said.
Earlier reports said the survivor was Swedish, but the company denied this. Company officials, speaking on condition of anonymity, said there were foreigners on board and the passenger list would be released on Sunday.
The aircraft, a 19-seat turboprop Beechcraft B1900C, was flying from the Angolan capital, Luanda, which lies around 1000km north of Lubango.
The cause of the crash, which occurred about 20km outside Lubango, was not immediately known. Company officials said the weather was misty and cloudy.
Among the victims were three Angolans employed by a Portuguese bank, Banco de Fomento Exterior, in Angola, the company said. Another bank employee and his wife, both of Angolan-Portuguese descent, also died in the crash, according to company officials.
Another Angolan, a regional manager for Angola's state oil company Sonangol, also was known to have been on the plane, the company said.
Over the past four years, more than 10 military and civilian planes have crashed in Angola, killing over 150 people.
Private companies charter aircraft to carry passengers and cargo across the vast former Portuguese colony because land mines and skirmishes between the army and Unita rebel group make road travel unsafe. - Sapa-AP