Tekfen signed the contract on 31 May, and the job will last for two-and-a-half years.

It covers the construction of a 300,000-tonne-a-year (t/y) low-density polyethylene plant (LDPE), the third Qapco has built at the site.

Germany's Uhde won the main $550m engineering, procurement and construction (EPC) contract for the project in May after lengthy negotiations with Qapco. Tekfen's job is a subcontract of the main deal.

Qapco produces 720,000 t/y of LDPE at its two existing units.

The plant will use excess natural gas ethylene produced by Qapco and its subsidiary Qatofin at their ethylene "cracker" plant at Ras Laffan.

Qapco is a joint venture of Industries Qatar, with an 80 per cent stake, and France's Total, with a 20 per cent stake.

Qatofin is a joint venture of Qapco, with a 63 per cent stake, Total, which has a 36 per cent stake, and Qatar Petroleum, with 1 per cent.

The Qatofin cracker and an associated linear low density polyethylene (LLDPE) plant at Mesaieed will start operating in the fourth quarter of 2009.