City gas companies like Indraprastha Gas Ltd and Adani Total Gas Ltd are mulling an increase in CNG prices after supplies of cheaper input gas was cut for the second time in a month, but the government officials say the retailers must give a cost breakup to justify the hike. The government, with effect from November 16, cut supplies of low-priced natural gas coming from old fields to city gas retailers by up to 20 per cent. This reduction came on the back of a 21 per cent reduction on October 16. City gas retailers IGL, which retails CNG in national capital and adjoining cities, Mahanagar Gas Ltd that does the same in Mumbai, and Adani Total Gas Ltd which operates in Gujarat and elsewhere, in regulatory filings flagged profitability concerns due to supply cut and hinted at price hike. Officials in the ministry of petroleum and natural gas however are unimpressed as they feel the retailers operate on "hefty" margins and can easily absorb the additional cost they may have to incur on