DUBAI (Reuters) - Saudi mall operator Arabian Centres is expected to sell $650 million in 5-1/2 year Islamic bonds at around 5.75% after receiving more than $1.2 billion in orders for the deal, a document showed on Tuesday. Price guidance on the sukuk was tightened to a range of 5.75% plus or minus 12.5 basis points, after initial guidance of around 5.875%, the document issued by one of the banks arranging the deal showed. The deal is expected to launch later on Tuesday.