Domestic natural gas price rose by 25 cents to $6.75 per mmbtu (million British thermal unit) for April after the previously decided annual increase kicked in, according to an oil ministry notification. The increase will marginally push up cooking costs for households using piped natural gas. Running costs of CNG vehicles may go up while city gas distributors and fertiliser makers will also be affected. The price ceiling for natural gas from difficult fields barely changed to $10.04 per mmbtu fo...