Shares in Pike River Coal (PRC) and its part-owner, NZ Oil and Gas (NZO), have been suspended from trading on the NZX after an explosion at PRC’s West Coast Mine on Friday afternoon.

Both suspensions were at the companies’ request, NZX said.

Both are for an indefinite period.

RELATED: Pike execs told investors high gas levels okay in 'wet' mine

Emergency operations to rescue the 27 miners still in the mine are continuing.

The dual-listed stocks were suspended in Australia late on Friday, when the New Zealand market was already closed.

PRC is 29.4% owned by NZO.

“This suspension will remain in place until such time as PRC is able to provide the market with a detailed update regarding the recent event at its Greymouth coal mine,” the NZX said.

NZO shares last traded in New Zealand on Friday at $1.20, down 3c, while PRC finished at $0.88, down 4c.