Trading has been halted in the shares of Pike River Coal on the New Zealand stock exchange.
Stock exchange operator NZX says the suspension remains in place until Pike River Coal knows more about the explosion at its West Coast mine and the condition of the trapped 29 workers.
Toxic gases have prevented rescue teams from entering the mine since the explosion on Friday afternoon.
Listed energy explorer New Zealand Oil & Gas, which has a 29% stake in Pike River Coal, has also halted trading in its shares on New Zealand's stock exchange.
Both companies placed trading bans on their shares on Australia's stock exchange on Friday, but not before Pike River's stock plunged 14%.
Pike River Coal shares fell 4% to 88 cents in New Zealand, though the effects of the explosion were not known before the market closed. They have fallen 28% over the past year.
Pike River Coal is due to repay a $25 million loan to New Zealand Oil & Gas by the middle of December and some analysts had expected the miner to seek more capital to repay the debt.
Production volumes have been lower than expected, delaying coal shipments.
