Despite default by somegenerating companies, Coal India has maintained supplies due to COVID-19 pandemic and the nationwide lockdown, an official said on Monday.The countrys largest miner has also extended the time limit for payment of coal, booked by its customers, by two more weeks till April 21 from April 7 announced earlier.The long pending demand of Usance LC is now implemented as an additional mode of payment along with Irrevocable Revolving Letters of Credit (IRLC) for the coal supplied to power producers, especially independent power plants.This will help the cash strapped power producers avail credit facility through their banks to tackle liquidity crunch."There had been defaults by both central and states generating companies as they are not getting paid by distribution companies and even so we are maintaining supplies and relaxing other terms," a senior coal India official told PTI.Immediately, details of dues cannot be acertained, officials said.CIL has also extended the validity period for lifting of coal under all auctions without any penalty. Earlier, failure to lift the ordered quantity of coal within a stipulated time period attracted forfeiture of earnest money deposit under auction schemes.Now, this clause has been done away with till the closure of lockdown period to non-regulated sector as well.The move comes amid a slew of measures that the Maharatna coal major has introduced to lessen the burden of its customers in the ongoing lockdown phase.Coal India is encouraging power companies importing coal to substitute their requirement of imported coal with domestic fuel.Coal stocks in the country now stand at 120 Million Tonnes (MTs) with pitheads of CIL heaped high close to 75 MTs. The rest 45 MTs of coal stock is at thermal power plants sufficient for 28 days consumption.