Saudi Arabia is pushing ahead with plans to open up its lucrative and closely-guarded energy industry to international firms.

About 40 energy companies are gathering in London to hear the terms and conditions that Saudi Arabia is offering in return for exploring, extracting and producing natural gas.

It is the mineral-rich kingdom's first ever licensing round, a common practice amongst many other countries who invite foreign firms to develop certain areas in return for a share of the profits.

Saudi oil minister Ali Naimi was previously thought to have opposed any attempt to welcome in foreign investors, fearing the kingdom would lose control of its own resources.

Saudi Arabia, the world's largest oil exporter, is also thought to have the fourth largest reserves of natural gas in the world.

Dash for cash

Mr Naimi has confirmed that three giant natural gas exploration areas are on offer, calling the tender "an important landmark in the history of the kingdom's petroleum industry".

"We are committed to creating an environment that is even more attractive to private investment," Mr Naimi told representatives from the oil firms.

The kingdom's previous attempts to open up its gas industry to foreign firms collapsed after a three-year bitter row over commercial terms.

Experts say Saudi's newfound willingness to open its doors to foreign oil firms is based on its need for cash.

Deadlines

Earlier this month, Shell and Total became the first western oil giants for 25 years to be given rights to develop gas reserves.

That project is on a much smaller scale than the original deals negotiated, but gives the firms a key foothold in the country.

This week's meeting is being held behind closed doors.

Foreign firms are invited to submit their bid after receiving final details within three months.

Saudi Arabia is expected to award the exploration contracts early next year.