March 28 (Reuters) - Genel Energy, one of a handful of foreign oil producers in Iraqi Kurdistan, slashed its reserves estimate for Taq Taq, its largest operational field, by about 66 percent and suspended its 2017 gross average production forecast for the field.

The company said it expected to book an impairment against the carrying value of its holding in the Taq Taq field by $181 million in its 2016 accounts, blaming significant uncertainties around the oil reserves in the field.

Genel estimated that Taq Taq had gross reserves of 59 million barrels of oil as of Feb. 28, down from the 172 million it had estimated in Dec. 31, 2015.

"Reduction in reserve estimates for Taq Taq is a consequence of a reassessment of the gross rock volume above the oil water contact and fracture porosity in the undrained cretaceous Shiranish reservoir," Genel said.

(Reporting by Esha Vaish in Bengaluru, editing by Louise Heavens) ((esha.vaish@thomsonreuters.com; +44 20 7542 1810; Reuters Messaging: esha.vaish.thomsonreuters.com@reuters.net; LinkedIn: https://in.linkedin.com/in/esha-vaish-9690b630 ))