MOSCOW, Sept 12 (Reuters) - Kazakhstan's oil output, excluding condensate, fell by 13% to 1.196 million barrels per day (bpd) (5.077 million tonnes) in August from 1.378 million bpd (5.850 million tonnes) in July, two sources citing daily output data said on Monday.

The fall in output was due to a sharp decline in production in the giant Kashagan oil field after a gas leak early in August, as well as planned output curbs in the Tengiz field due to regular maintenance.

Kazakhstan's Energy Ministry did not immediately respond to a Reuters' request for comment.

Kazakhstan uses a conversion rate of 7.3 barrels for 1 tonne of crude oil. (Reporting by Reuters; Editing by Jon Boyle)