DUBAI - Saudi Arabia's planned triple-tranche international bond issue is expected to be $12.5 billion in size, and order books total over $40 billion, sources familiar with the matter said on Wednesday.

The bond, split into three tranches maturing in March 2023, March 2028 and October 2047, will price later on Wednesday.

Initial price guidance for the three tranches was in the 130 basis points over U.S. Treasuries area for the long five-year tranche, 165 bps over for the long 10-year and 200 bps over for the 30-year.

Guidance was tightened by 15 bps, with the bond expected to price within a range of plus or minus 5 bps across the three tranches, IFR reported on Wednesday.

GIB Capital, Goldman Sachs International, HSBC, J.P. Morgan, and MUFG are the joint lead managers and joint bookrunners.

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