LONDON, Sept 5 (Reuters) - Kazakhstan's energy ministry

has requested shareholders in the giant Kashagan oilfield delay

to next year maintenance planned to begin at the site in

October, trading sources with knowledge of the matter said.

In a letter to partners in the North Caspian Operating

Company (NCOC) consortium that operates Kashagan, the ministry

cited concerns over natural gas shortages as the reason for the

requested delay, two of the sources said.

A decision was expected to be made on Sept. 10, they added.

The 400,000 barrels per day field was scheduled to be shut

down in October for maintenance that was planned to last 28

days.