Citigroup has sold its controversial commodity unit Phibro to Occidental Petroleum for a cut price after intense pressure from the US government over the compensation of its star trader Andrew Hall, according to people close to the situation.

The sale, announced on Friday, underlines the influence the authorities are exerting on companies that rely on taxpayers’ money and raises concerns over government interference. Citi has received $45bn in federal aid and has ceded a 34 per cent stake to the government.