Opec and non-Opec countries are studying a Venezuelan proposal for a heads-of-state summit to address low oil prices, the energy minister of Qatar said on Thursday. "The different countries are studying this proposal and if there was a response from Opec and outside Opec then OK," Qatar's Mohammed al-Sada said. "But we are in the study phase." Opec member Venezuela has been campaigning for action to address low oil prices, which at below $48 a barrel are less than half their level of June 2014. Sada is the alternate president of Opec this year.