With an annual capacity of 300,000 tonnes, the facility will make Qapco the largest single-site producer of low-density polyethylene in the world and Qatar a key member of the global club of major petrochemical producers and exporters.
Qapco's polyethylene output will see a 75% increase - to 700,000tpy from 300,000tpy with LDPE 3 attaining full capacity in January next year.
Qapco's two existing production lines - LDPE 1 and 2 - already account for more than 400,000 tpy.
Products from LPDE 3 will be sold under the brand name "Lotrene throughQapco's global marketing network, which comprises some 30 own offices and logistic facilities around the world. Currently, the company has some 4,500 corporate customers in 145 countries worldwide.
According to Qapco, the new facility will produce "prime high pressure grade LDPE, thus positioning the company as a global leader in LDPE production.
Currently, Qapco's manufacturing facilities consist of an 800,000 tpy ethylene plant, 70,000 tpy sulphur processing facility, in addition to the two existing LDPE plants.
LDPE 3 was conceptualised in 2002, when Qapco identified "huge potential for the material in view of its global demand.
Construction began in 2009 after the foundation stone for the project was laid by HH the Heir Apparent, Sheikh Tamim bin Hamad al-Thani.
The engineering, procurement and construction (EPC) contract for LDPE 3 was awarded to Germany's Uhde. The technology was licensed by Basell.
Qapco vice-chairman and CEO, Dr Mohamed Yousef al-Mulla, said the LDPE 3 started production in August with the capacity now reaching 93%.
"We are gradually increasing the output and following the final performance test we hope to attain full production capacity by January 2013. We may be able to go even up to 330,000 tpy, al-Mulla said.