Shares of Rabigh Refining and Petrochemical Co. (Petro Rabigh) escalated by almost 150% above their initial public offering price on their first day of trading, closing at SR52. Petro Rabigh priced its IPO at SR21 per share. Saudi Aramco and Japan's Sumitomo Chemicals own 37.5% each of Petro Rabigh. Balance 25% was sold this month to Saudi investors through the IPO in a SR4.6 bln (US$1.2 bln) IPO. This is the first time Aramco has offered shares in one of its affiliates to the public.