BAKU -- Development of a massive natural gas field in the Caspian Sea is being held up because of continuing uncertainty over whether the gas can be sold to Turkey, the head of the project said Monday.

David Woodward, head of oil major BP's operations in Azerbaijan, said approval for the start of full field development at Shah Deniz was to have been given in July but has now been pushed back to late October.

"There are still a number of issues relating to the Turkish market and the sales and purchase agreement that was signed between Azerbaijan and Turkey last year," Woodward told AFP. "We need to resolve the issues relating to that agreement before it will be possible to sanction (full field development of Shah Deniz)."

Shah Deniz, which lies in Azerbaijan's sector of the Caspian Sea, contains an estimated 400 billion cubic meters (14,000 cubic feet) of gas, making it a world-class field and the biggest gas discovery in the Caspian to date.

The consortium operating the field plans to build a gas pipeline from Azerbaijan to Turkey to supply the domestic market there.

In March 2001 the governments of Azerbaijan and Turkey signed an agreement under which Turkey committed itself to importing six billion cubic meters of gas from Shah Deniz each year.

However, some industry insiders and analysts have warned that the project is not feasible at the moment because Turkey's economic turmoil is depressing demand for natural gas in the country.

The Shah Deniz consortium says it is still confident a solution can be found and that full field development and pipeline construction will both go ahead.

The consortium comprises BP, which is also the project operator, Azeri state oil company Socar, Statoil, TotalFinaElf, Lukoil, OIEC and TPAO.