State-owned Oil and Natural Gas Corp (ONGC) has signed a cooperation agreement with GAIL India Ltd for getting better market price. The agreement statements say, GAIL will get the first right on all gas that ONGC will produce from any of its fields in future. But in case GAIL is unable to get a 'good' price within 30 days, ONGC will take back the marketing right. GAIL would also market some of the chemicals to be produced from the Dahej petrochemical complex being set up by ONGC Petro-additions Ltd, OPaL, a subsidiary of ONGC. GAIL has 19 per cent stake in OPaL. GAIL will be a co-promoter of the 1.1 million tons ethylene cracker petrochemical complex that OPaL is setting up at Dahej SEZ at a capital cost of 19,535 crore rupees. The agreements will be initially valid for three years and can be extended thereafter. The two companies also reached an understanding for possible swapping of available natural gas with a view to optimise the logistics and costs.