British explorer Cove Energy Plc has put itself up for sale, raising the prospect of a deal that analysts said could be worth some $1 billion (642 million pounds) and would test big oil companies' interest in the emerging gas basins of east Africa.

Cove shares traded up 8.4 percent at 122 pence by 0844 GMT after hitting a record 127.75p.

We see this as a positive move that will reduce concerns that Cove might wait too long to monetise its Mozambique assets and have to raise further funding in mid-2012 to meet increasing capex (capital expenditure) requirements of the project, Michael Alsford, oil analyst at Citigroup, said in a research note.

Cove said in December it had offered data to parties who had expressed an interest in acquiring its 8.5 percent stake in the Rovuma Area 1 block in Mozambique, a liquid natural gas project which is moving towards the development stage and is led by U.S. explorer Anadarko Petroleum Corp .

Industry executives said all the big oil companies including BP Plc , Royal Dutch Shell Plc and Exxon Mobil Corp would probably look at Cove's books.

Rovuma Area 1 represents a substantial portion of Cove's asset value within the portfolio of focused and complementary assets which the company has built in east Africa. As such the directors have unanimously agreed that a sale of the company may be appropriate at this time, Cove said in a statement.

In addition to the sale process -- to be conducted by its advisor Standard Bank -- Cove said it would continue to examine other strategic options including the sale of the Rovuma Area 1 stake rather than the whole company.

Cove said Britain's Takeover Panel had agreed that potential suitors need not be publicly identified and that they would not be subject to the usual 28 day rule for making a formal bid.

Cove was valued at 552 million pounds on the basis of its closing stock market price on Wednesday.

(Reporting by Matt Scuffham and Tom Bergin; Editing by Rhys Jones and David Holmes)