Kuwait said the budget for building its Al-Zour refinery complex remained unchanged at 4 billion dinars ($15 billion), after awarding $8.4 billion of contracts to four South Korean firms and one Japanese.

'There are other expenses such as supervision, procurement, material and construction (PMC) costs, and licence costs,' Assad Al-Saad, deputy chairman of state refiner Kuwait National Petroleum Co (KNPC), told Reuters on Monday.

A $2 billion engineering, procurement and construction (EPC) contract for the 615,000 barrels per day (bpd) complex remains to be awarded, Saad said. US engineering firm Fluor Corp is Al-Zour's project manager and will oversee the award of the EPC contract.

KNPC on Sunday awarded a package worth $4 billion to build crude distillation units to a combination of Japan's JGC Corp, and South Korea's GS Engineering and Construction Corp.

A $2 billion contract went to South Korea's SK Energy to build a hydrogen production unit, while Daelim Industrial won a $1.2 billion contract to set up storage tanks.

'The $8.4 billion is just an initial estimate,' independent Kuwaiti oil analyst Kamel al-Harmi said. 'It will go up when they build the refinery.'    
Hyundai Engineering & Construction  won a $1.1 billion deal for marine export facilities, while another project was won Fluor, KNPC said, without giving its value.

'There is a tender that we did not float until now which is the utility and offsite ... it is about $2 billion,' he said.

A KNPC official, who did not want to be identified, told Reuters last month the refinery complex could cost as much as $19 billion as it is considering adding units.

As the contracts are based on a cost-plus profit-margin basis, the project could end on budget, Saad said. Under the system, companies typically submit detailed cost estimates for the refinery, plus their required profit margin.

'KNPC is protecting itself against an escalation of costs such as metal prices,' Harmi said.

Kuwait had initially budgeted about $6 billion for the refinery several years ago, but the expected cost has soared on rising costs for raw materials and manpower.

The world's seventh-largest oil exporter plans to boost refining capacity to 1.415 million bpd from 930,000 bpd with the new plant, and upgrade at its Mina Abdullah and Mina Ahmadi refineries.

The Al-Zour project is to replace its aging 200,000 bpd Shuaiba refinery, which has been hit by several accidents. Al-Zour would start operating in 2012, two years later than initally planned, KNPC said on Sunday. - Reuters