It will continue through to Friday, June 9. A total of 360 companies from 30 countries are exhibiting this year, and 90% of the exhibitors are first-timers here.

The number of participants was smaller last year, as 330 companies from 28 countries took part in the Baku exhibition.

Organizers told Itar-Tass the group of Russian exhibitors is one of the biggest.

They name two factors for this, including the Year of Russian in Azerbaijan and the interest that Russian businesses have in developing the Caspian oil and gas fields.

Russian corporations show expansive interest in cooperation with their Azerbaijani counterparts in the industry and in contacts with leading manufacturers of upstream technologies.

International interest towards Caspian Oil & Gas 2006 has been whipped up by commissioning of the Baku-Tbilisi Ceyhan pipeline that pumps Caspian crude to the Turkish Mediterranean port of Ceyhan and has a throughput capacity for 50 million tons of crude a year.

The pipeline helps avoid sea haulage by tankers via Black Sea straits on the way to Western markets.

Also, the exhibitors' interest is apparently linked to the forthcoming commissioning of the Baku-Tbilisi-Erzurum gas pipeline.

That pipe has a capacity for 20 billion cubic meters of natural gas a year and it is expected to come on stream this fall.

The itinerary of the exhibition includes a two-day conference on energy security and delivery of Caspian crude to international markets.

The participants in it will look at crucial aspects of oil and gas development strategies and engagement of leading international oilfield operators and technology manufacturers in the production process.

Experts claim the Caspian Sea area has 200 billion barrels of crude oil and 640 cubic feet of natural gas, which stands at around 15% of global hydrocarbon reserves.

President Ilham Aliyev of Azerbaijan took part in the opening ceremony Tuesday.