Cnooc (CEO.NYSE, 0883.HKG) issued US$4 billion worth of bonds on Wednesday in a deal that was heavily oversubscribed by investors, attracting more than US$20 billion in orders, The Wall Street Journal reported. Proceeds from the bond sale will be used to repay loans that financed the oil company’s acquisition of Canadian oil-sands operator Nexen. last year. Some foreign investors said the bonds were a bargain as they look to buy highly rated bonds that offer more lucrative yields than US-based companies. This issue ties a $4 billion bond deal in May 2013 for Cnooc’s largest debt sale in the US.