Citigroup stands to miss out on fees for the biggest takeover in Asia this year, with Lone Star, the Dallas-based private equity fund it is advising, threatening to scrap a $7.2bn (€5.6bn) deal.

Lone Star said yesterday it may walk away from its sale of Korea Exchange Bank, a deal from which it stands to make as much as $4bn, if prosecutors in the country fail to conclude an investigation in the next three weeks.