SEOUL, Nov 4 (Reuters) - South Korea intends to buy four Global Hawk unmanned aircraft, made by Northrop Grumman Corp , for about 900 billion won ($848 million), an official at the country's defense acquisition agency confirmed on Monday.

Lee Young-geol, the administrator of South Korea's Defense Acquisition Program Administration (DAPA), said in a parliamentary audit late on Friday that South Korea "has plans to sign a contract next year to adopt Global Hawks in 2017".

The purchase would be conducted through the U.S. Foreign Military Sale (FMS) programme, and was likely to be signed in the first half of 2014, said the official who was not authorised to to speak about the deal before its terms were fixed.

The budget for the purchase had yet to be earmarked and the exact terms of purchase had yet to be decided, the official added.

The U.S. congress approved the export of the Global Hawk system to South Korea earlier this year.

Local newspapers have previously reported that South Korea's military had received approval from the country's finance ministry to increase the budget for the purchase from an original 480 billion won.

A spokesman for DAPA declined to elaborate beyond the administrator's comments.

Northrop declined to confirm or deny South Korea's stance, but added it continues to "work closely with the U.S. Department of Defense and Korean government to ensure their growing intelligence, surveillance and reconnaissance requirements are met with Global Hawk."