DUBAI, May 23 (Reuters) - Bahrain's Al Baraka Banking Group BARKA.BH has tightened pricing guidance for its planned U.S. dollar sukuk issue to the 8-8.125 percent area, according to a document issued by one of the banks leading the deal on Tuesday.

Initial guidance was released earlier in the day in the low- to mid-8 percent area.

Order books for the perpetual sukuk, expected to be of benchmark size, topped $1.25 billion, the document showed. The Islamic bond is expected to price later on Tuesday.

(Reporting by Davide Barbuscia; Editing by Andrew Torchia) ((Davide.Barbuscia@thomsonreuters.com;))