 To build his oil and aviation empire Efromovich bought Avianca, Colombia's national airline, in 2004, for US$ 2 billion, plus the assumption of US$ 220 million in debt and leasing liabilities.Initially performing only nondestructive testing for the Brazilian-government-run oil company, Petrobras, Efromovich developed more business to the point of building and leasing oil rigs.His other businesses include power plants, shipyards and products for the medical industry.