Cnooc’s Nexen acquisition marred by insider trading charges

A company controlled by Chinese billionaire Zhang Zhi Rong has become embroiled in an insider trading scandal surrounding Cnooc’s record $15.1 billion acquisition of Canadian oil and gas company Nexen.

On Friday, securities regulators in the US froze the assets of Well Advantage after its trading in Nexen shares attracted suspicion. The SEC said that the British Virgin Islands company and other unknown investors had stockpiled shares in Nexen after gaining possession of “material non-public information about the impending acquisition”, which stood to make them a profit of more than $13 million when they tried to liquidate the entire position on Thursday.

“Well Advantage and these...