OPEC and non-OPEC oil producers need to work together to tackle a global stocks overhang so oil prices can recover and investments in new fields could be made, OPEC Secretary-General Abdullah Al Badri said. "It is vital the market addresses the issue of the stock overhang. As you can see from previous cycles, once this overhang starts falling, then prices start to rise," he told a conference in London, Reuters reported. "Given how this developed, it should be viewed as something OPEC and non-OPEC tackle together. Yes, OPEC provided some of the additional supply last year, but the majority of this has come from non-OPEC countries. Badri said it was crucial that all major producers come up with a solution, as the market needs to see inventories come down to levels that allow prices to recover and investments to return. "The current environment is putting this future at risk. At current price levels, it is clear that not all of the necessary future investment is viable," he said.