HSBC Holdings and Goldman Sachs are being said to advise UAE’s ADNOC on a 40% stake sale of its $20 billion refining unit, valued at around $8 billion. The company is looking at offers from potential partners who could buy stakes in its refining business. ADNOC had, earlier, revealed plans to invest some $45 billion in refining and petrochemical projects, in its bid to expand capacity to process oil.