(Adds details)DUBAI, May 7 (Reuters) - Majid Al Futtaim, a UAE-based developer and shopping mall operator, has started marketing 10-year U.S. dollar-denominated "green" Islamic bonds, or sukuk, at about 245 basis points over mid-swaps, a document showed on Tuesday.The proceeds of the sukuk will back environmentally-friendly projects in areas such as renewable energy and sustainable water managemen