DUBAI, May 16 (Reuters) - Qatar Islamic Bank QISB.QA (QIB), the Gulf state's largest Islamic lender by assets, has set at 135 basis points (bps) over mid-swaps the final spread for its planned five-year dollar sukuk, a document issued by one of the leading banks and seen by Reuters showed on Tuesday.

Initial price guidance was released earlier in the day at 145-155 bps over mid-swaps, before being tightened to 140-145 bps over the benchmark.

Order books for the senior unsecured Islamic bond, part of a $3 billion sukuk programme, topped $2.1 billion, the document showed.

(Reporting by Davide Barbuscia; Editing by Mark Potter) ((Davide.Barbuscia@thomsonreuters.com;))