DUBAI, June 11 (Reuters) - Pricing guidance for a ten-year sukuk issue by Emaar Malls Group, a unit of Dubai&aposs Emaar Properties EMAR.DU , was tightened further on Wednesday, with final guidance issued at 185 basis points over midswaps plus or minus 2.5 bps, a document from lead arrangers said.The size of the issue will be $750 million, the document showed.On Tuesday Emaar Malls, which also pla