CORRECTED-UPDATE 1-Western Digital sees return to pre-flood Thai output by Sept

* Plan to resume ops of Navanakorn plant in March

BANGKOK Jan 17 (Reuters) - Western Digital Corp expects its two factories in Thailand to return to pre-flood production levels by September after the planned resumption of operations at its Navanakorn plant in March, its chief executive said on Tuesday.

Western Digital, a hard drive manufacturer hit hard by the floods, resumed production at its Bang Pa-in plant in central Ayutthaya on Nov. 30, President and Chief Executive John Coyne said at an industry seminar.

"Our focus today is on bringing back our capacity to rapidly support our customers," Coyne said.

Coyne said he believed the floods would have only a temporary impact and welcomed the government's plan to improve Thailand's water management system.

The California-based firm, which vies with Seagate Technology for the title of the world's largest maker of hard drives, had warned of tighter global supply until early this year.

Western Digital has manufacturing facilities in Bang Pa-in Industrial Park in Ayutthaya province and Nava Nakorn Industrial Park in Pathum Thani province, both of which were severely hit by floods.

Thailand produces around half of global hard drives through Western Digital, Seagate and Hitachi Global Storage Technologies.