Cove, which owns an 8.5 percent stake in a huge gas discovery off the coast of Mozambique, put itself up for sale in January and is now at the centre of a bidding war having received approaches from oil major Shell and Thai group PTT .
Minerals Minister Esperanca Bias said on Thursday that the government of the East African country wants to introduce a capital gains tax on the sale to benefit from a transaction linked to its own resources.
The company is seeking clarity on this issue and will make further announcements when or if appropriate, said Cove in a statement on Friday, adding that the sale process is continuing.
Some oil and gas firms have tax stabilisation clauses written into their agreements with the host country which prohibit governments later applying new taxes.
If Cove's agreement has such a clause, it could take the Maputo government to international arbitration if it sought to levy a new capital gains tax.
Shares in Cove closed at 226 pence on Thursday, trading higher than the 220 pence per share offer planned by PPT and Shell's 195 pence proposed bid.
(Reporting by Sarah Young and Tom Bergin; Editing by Paul Sandle)