Qatar Petroleum and Shell said they had decided not to proceed with their $6.4 billion Al Karaana petrochemical project in the Gulf state, the region's second big energy project to be shelved since oil prices began to plunge late last year. Prices quoted by contractors to build the huge complex showed the project was "commercially unfeasible, particularly in the current economic climate prevailing in the energy industry", the two companies said in a joint statement on Wednesday. State-owned Qatar Petroleum and Shell had agreed on the project in December 2011; they were to build a petrochemical complex in the Ras Laffan Industrial City, with the Qatari company owning 80 percent and Shell 20 percent. The Al Karaana project had appeared to face delays even before oil prices started to tumble.