Rockhopper had initially gained but by late afternoon its shares were down by nearly 11%
Premier has agreed to farm into 60% of Rockhopper's interests in its licences in the North Falkland Basin including the Sea Lion development and adjacent discoveries, Casper and Casper South.
Premier will assume operatorship of the Sea Lion development, located in licences PL032 and PL004b
Premier has agreed to pay Rockhopper an upfront cash consideration of $231m, payable on completion.
Premier has committed to carry Rockhopper's portion of development costs in relation to the development area up to the first $1.8bn of gross capital expenditure.
Rockhopper chief executive Sam Moody said: "I am delighted that we have been able to secure such a high quality partner for our work in moving the Sea Lion development forward - Premier have an outstanding track record in developing and running producing assets and also have significant international experience.
"This is an excellent transaction for the company and its shareholders. It helps crystallise the value of our discoveries in the North Falkland Basin area centred on the Sea Lion field, as well as providing the funds to examine further the remaining potential of our acreage in the region."
The deal had little effect on Premier's share price - up by less than 1% in late afternoon trading.
Total [LON:TTA] has acquired an additional 6% interest in the Ichthys liquefied natural gas (LNG) project in Australia from its partner INPEX.
As a result Total's overall equity stake in the Ichthys LNG project grows from 24% to 30%.
The acquisition does not impact any of the LNG offtake agreements with the entire annual production of LNG (8.4m tons per annum) having already been sold for 15 years. Total, through its gas trading subsidiary, will purchase 0.9m tons per year of this LNG.
Yves-Louis DarricarrÃ¨re, President of Total Exploration & Production, said: "We are delighted to have increased our stake which demonstrates our confidence in this world class Ichthys LNG project.
"This further enhances our presence in Australia and our position as supplier in the Asian LNG market, the fastest growing market offering high value prices linked to oil. This move also consolidates Total's strategy as a leading LNG player."
The transaction remains subject to approval by the Australian authorities.
Oil producer Exillon Energy [LON:EXI] has commissioned its own entry point to the Transneft pipeline network.
All regulatory approvals have been obtained, and 100% of production from Exillon West Siberia is now transiting via this facility.
Exillon had previously transported oil approximately 200km by road to reach an entry point owned by a third party.
The new entry point is approximately 100km from its oil fields, and transportation costs will fall accordingly.
The company estimates that the use of the entry point will increase earnings before interest, tax, depreciation and amortisation generated by production from Exillon WS by approximately $1.50 per barrel.
Matra Petroleum [LON:MTA] has commissioned a seismic survey on its 100%-owned Sokolovskoe oil field in Orenburg, Russia.
The survey - which will be carried out by Orenburgskaya Geophysical Expedition, a subsidiary of Geotech - will begin on 1 August and will include 100 km of 2D seismic and 60 sq km of 3D seismic.
The survey will take up to two months with preliminary results expected by the end of 2012 and final results in the first quarter of 2013.
This survey is designed to evaluate the prospectively of the Sokolovskoe field ahead of any further financial commitment by the company and as part of a wider strategic review.
Caza Oil & Gas [LON:CAZA] was one of the sector's biggest risers after it revealed successful results from the Bradley well and that it had sold its San Jacinto property in Midland County, Texas - which includes the Caza Elkins 3401 and 3402 wells - for $6.1m.
[LON:AUR] Aurum Mining share price was -0.25p at 3p
[LON:BOR] share price was -6.12p at 60.38p
[LON:CAZA] share price was +0.63p at 7.5p
[LON:CHAR] share price was -10.75p at 113.5p
[LON:DES] Desire Petroleum share price was -0.25p at 21p
[LON:DGO] Dragon Oil share price was -11p at 561p
[LON:ENQ] share price was -2.35p at 108.15p
[LON:EXI] share price was +0.5p at 97p
[LON:FOGL] Falkland Oil and Gas Limited share price was -5.25p at 83.75p
[LON:GKP] Gulf Keystone Petroleum share price was -5.37p at 201.38p
[LON:GPX] share price was -0.5p at 94.5p
[LON:INDI] share price was +12.5p at 997.5p
[LON:PET] Petrel Resources share price was 0p at 4.75p
[LON:PMO] Premier Oil share price was +3.75p at 362.55p
[LON:RKH] share price was -29.5p at 244.5p
[LON:RPT] Regal Petroleum share price was 0p at 16.5p
[LON:TTA] share price was -0.01p at 35.79p
[LON:XEL] share price was -7p at 72.5p
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