(Adds no comment from Petrofac, cost, other projects)
KHOBAR, Saudi Arabia, Aug 16 (Reuters) - Saudi Aramco <IPO-ARMO.SE> has received bids from international engineering firms to expand the Hawiyah gas plant, industry sources said on Wednesday.
They said the companies that submitted their proposals, on Sunday, were: South Korean Samsung Engineering, Spain's Tecnicas Reunidas, Taiwan's CTCI, Italy's Saipem, Britain's Petrofac, India's Larsen & Toubro (L&T).
South Korea's Hyundai Engineering and Hyundai Development Co Engineering & Construction (HDEC) bid together as a consortium.
Saudi Aramco said it would not comment as did Hyundai and Petrofac. Tecnicas Reunidas was not available for comment.
L&T and Samsung Engineering confirmed to Reuters they bid for the project.
Aramco plans to expand the processing capacity at Hawiyah by 1.3 billion standard cubic feet per day (scfd). It currently processes 2.5 billion scfd of gas.
Companies will submit bids next week to build gas compression stations at Haradh and Hawiyah.
The expansion of the Hawiyah gas plant and the new gas compression stations at Haradh and Hawiyah is expected to cost more than $4 billion, industry sources estimated.
Hawiyah and Haradh are part of Ghawar, the world's largest onshore oilfield.
Raising gas production is key to Saudi Arabia's plan to diversify its energy mix by cutting the use of crude oil and liquids for power generation while allocating more gas to other industries it aims to develop.
Despite falling oil prices, Saudi Aramco is pushing ahead with oil and gas projects that it has highlighted as a priority for the long term to keep the world well supplied with oil while meeting gas demand domestically.
It plans to nearly double gas production to 23 billion standard cubic feet a day in the next decade.
Its CEO Amin Nasser said last month the firm plans to invest more than $300 billion over the coming decade to reinforce its pre-eminent position in oil, maintain spare oil production capacity, and pursue a large exploration and production program centering on conventional and unconventional gas resources.
But apart from those targets, Aramco also aims to enhance its long-term revenues by building a diversified growth platform and through international gas opportunities, it said last week in a statement in its internal publication, the Arabian Sun. (Reporting by Reem Shamseddine, Promit Mukherjee in MUMBAI, Yuna Park in Seoul, Robert Hetz in Madrid; Editing by Jeremy Gaunt)