The orders issued by the Securities Commission of Papua New Guinea follow alleged breaches of the PNG Capital Market Act.
In a statement issued on Wednesday, Oil Search says it will legally challenge the orders.
According to Oil Search, the company had obtained valid approvals for its recent capital raise, completed on 28 May 2020, from the Executive Chairman of the Securities Commission of PNG.
However, the Acting Chairman of the Securities Commission of PNG issued orders including that trading of Oil Search shares on PNGX be suspended from 2 June 2020.
The order is based on allegations that Oil Search breached the PNG Capital Market Act by failing to obtain approval from the Securities Commission for the PNG Retail component of its recent capital raising.
Oil Search says it has at all times acted properly and complied with all its legal obligations.
The company says it disputes the validity of the orders issued and will vigorously defend its position by challenging the lawfulness of the orders in the National Court.
They remain confident that the approvals that it received are valid.
Oil Search says Trading of Oil Search shares on the Australian Stock Exchange (ASX) will continue as normal.