Leni Gas and Oil (LON:LGO) was the sector's biggest faller - down nearly 15% in late afternoon trading - despite pre-tax losses for the year to the end of December narrowing to £3.91m in from £10.29m.
Revenues increased to £3.4m from £2.3m and gross profits rose to £1.1m from £523,000.
Executive chairman David Lenigas said: "During the year the board has been focused on establishing the value of the Spanish assets and increasing our longer term exposure to the onshore oil development potential in Trinidad.
"The new business development activities in Trinidad have seen us successfully add roughly 5200 net acres of exploration and development leases, a six-fold increase, in a range of transactions due to complete in 2012.
"This marks a turning point in our portfolio development and we expect to be able to report positively on these investments in the years ahead."
Independent Resources (LON:IRG) was another of the sector's biggest fallers after it said it expected a pause in its Rivara underground gas storage project which is in the area affected by the recent earthquake in Italy.
The company said seismologists who have studied the natural seismicity in the area on behalf of the company have documented many seismic events similar to the recent earthquakes.
Events of this magnitude have an estimated recurrence of approximately every 230 years, with a predictably large uncertainty.
This seismicity is due to a large underlying plate that compresses as it moves north and this movement is independent of the much more superficial geologic system lying above it.
There are a number of existing natural gas fields and storage facilities in proximity of the affected area and these remain unaffected and in operation.
Heavily regulated gas storage facilities are engineered for any potential risks.
The company's planned operations prior to construction of the Rivara gas storage project include extensive in-situ measurements and geo-mechanical modelling. In parallel, the Company has planned extensive geochemical and seismic monitoring during the life of the project.
The company said: "The tragic events that have affected Emilia Romagna are the subject of intense study by the competent authorities and will require time to interpret and verify for consistency with the models.
"The company has already made all its data and studies available to the authorities to assist with this analysis, and has committed to contribute more going forward.
"The company expects a pause for the project and considers this understandable under the circumstances."
Europa Oil & Gas (LON:EOG) has received a highly encouraging competent person's report for its core assets in the UK and France - and specifically its Bearn des Gaves permit containing the Berenx Deep and Berenx Shallow gas prospects in the Aquitaine Basin.
The report by ERC Equipoise shows a 50.5 MMboe net mean unrisked resource for all audited UK producing/exploration licences and the Berenx Deep discovery in onshore France.
* 277 bcf net mean contingent resource for Berenx Deep gas discovery located close to giant producing gas fields
* 0.65 MMbbl remaining net 2P oil reserves for three UK onshore producing fields - West Firsby, Crosby Warren and Whisby
* 3.7 MMbbl net mean unrisked prospective oil resources for three UK onshore prospects - Broughton, Wressle and Holmwood
Europa chief executive Hugh Mackay said: "I am delighted to have received this independent assessment of Europa's UK and French licences which supports our view that our UK exploration assets, including Wressle, Broughton and Holmwood each have the potential to create significant value for shareholders, while Berenx in France could be the company maker we believe it is.
"At 50.5 MMboe the CPR's estimate of our core recoverable reserves and potential resources provides a solid asset backing to our current market valuation and will also play a key role in our ongoing negotiations with potential partners, specifically regarding our French permits.
"In the meantime, we remain on track to participate in the drilling of the Wressle prospect in the UK later this year which we rate as having a one in three chance of materially adding to our current production of 200 bopd."
Endeavour International (LON:ENDV) has completed the acquisition of an additional 23.43% working interest in the Alba field from ConocoPhillips.
The Alba oil field - which is located in block 16/26a in the Central North Sea - is a late Eocene reservoir that has been producing since 1994.
Endeavour's newly-acquired working interest combined with its previous ownership position takes the company's total working interest in the field to 25.68%.
As a result of the completion of the additional working interest in the Alba field, the net proceeds from the 2018 notes offering have been released from escrow.
The proceeds have been used to fund the acquisition and to repay outstanding amounts under the senior term loan.
Oil giant BP (LON:BP.) plans to sell its stake in Russian oil company TNK-BP which was set up with Alfa Access Renova in 2003.
BP says it has received unsolicited indications of interest over its shareholding and has notified Alfa Access Renova of its intention to pursue a potential sale.
BP says there can be no guarantee that any transaction will take place and a further announcement will be made when and if appropriate.
US-focused shale oil firm Nighthawk Energy's (LON:HAWK) work-over programme on its operated project at Jolly Ranch in Colorado is on schedule to be completed this month.
Nighthawk says plans for new drilling are well-advanced with permitting of 15-25 locations under way and locations for an initial four new wells have been selected.
The company also says that overhaul and refurbishment of topside facilities and environmental remediation work continues.
Chairman Stephen Gutteridge said: "The scale and extent of the work required to provide reliable, fit-for-purpose production facilities that meet required operating standards has been unwelcome, has absorbed resources and held back production.
"However, I am pleased that we have largely worked through these problems and are now able to focus on the new wells to be drilled in the second half of 2012.
"Our extensive geo-science work has identified excellent locations that strongly correlate with known significant producing wells on nearby acreage and we expect to confirm the drilling timetable in the coming weeks."
(LON:AUR) Aurum Mining share price was +0.01p at 2.88p
(LON:BOR) share price was -4.25p at 67.75p
(LON:BP.) BP share price was +7.33p at 402.23p
(LON:CHAR) share price was -0.62p at 83.13p
(LON:DES) Desire Petroleum share price was -1p at 23.5p
(LON:DGO) Dragon Oil share price was -16.62p at 482.13p
(LON:ENQ) share price was -6.2p at 115.3p
(LON:EOG) Europa Oil & Gas (Holdings) share price was -0.25p at 6.38p
(LON:FOGL) Falkland Oil and Gas Limited share price was -4.37p at 90.88p
(LON:GKP) Gulf Keystone Petroleum share price was -8.12p at 187.88p
(LON:GPX) share price was -1.62p at 88.38p
(LON:INDI) share price was -25.25p at 874.75p
(LON:IRG) share price was -3.5p at 31p
(LON:LGO) share price was -0.11p at 0.67p
(LON:PET) Petrel Resources share price was 0p at 4.5p
(LON:RKH) share price was -19.75p at 282p
(LON:RPT) Regal Petroleum share price was -0.5p at 21.75p
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