Azerbaijan has signed three major energy contracts to develop its oil and gas fields on the Caspian Sea.

The deals are together worth about four-billion dollars.

The bulk of the investment comes from a consortium of Italian, Japanese, Turkish and Spanish companies which bid for the Kurdashi field in the south.

Energy analysts say the deals mean that many of the big concessions in Azerbaijan are now decided.

The Azeri section of the Caspian is thought to hold about eight-billion tonnes of oil.

That's less than neighbouring Kazakhstan, but Azeri officials say Baku's position to the west of the sea makes its reserves easier to exploit.