* Siemens to supply driverless trains, related systems
* Subway to have strong air conditioning, sand-proof seals
* Order is part of 7.5 bln euro contract already announced
* Total of $22.5 bln worth of orders awarded in July
FRANKFURT, Oct 10 (Reuters) - Siemens's share ofa major contract to supply trains for a new subway system in theSaudi Arabian capital of Riyadh is worth 1.5 billion euros ($2billion), the German group said on Thursday, confirming itsbiggest ever rail engineering order from the region.
The contract is part of a total of $22.5 billion worth oforders awarded to three foreign-led consortia by Saudi Arabia inJuly for the design and construction of the metro rail system inRiyadh.
The project, which will involve six rail lines extending 176kilometres (110 miles) and carrying electric, driverless trains,is the world's largest public transport system currently underdevelopment, Saudi officials have said.
Siemens said in a statement on Thursday it would supplydriverless subway trains, electrification systems and signallingtechnology for two of the six lines.
Flush with cash after more than two years of high oilprices, Saudi Arabia is pumping billions of dollars intoinfrastructure projects designed to improve living standards andease social discontent in the wake of the 2011 uprisingselsewhere in the Arab world.
The government also says it wants to upgrade the country'sinfrastructure to help the economy diversify beyond oil, makingit less vulnerable to any future plunge of global oil prices.
The German engineering group will deliver 74 subway trainsequipped with an extra-strong air conditioning system to copewith the extreme heat as well as special seals and filters inbrakes and doors to cut down on the amount of sand that makesits way into the train cars.
The order is part of a 7.5 billion euros ($10.14billion)contract awarded to a consortium led by U.S.-basedBechtel.
Other major orders for the subway system included a $7.82billion contract awarded to a consortium led by Spain's Fomentode Construcciones y Contratas and a $5.21 billion orderfor a group headed by Italy's Ansaldo STS.
- Saudi Arabia