Petsec Energy is the latest producer to be belted by plunging gas prices, with the company forecasting a first half loss of up to $US6 million ($A5.81 million).

The average gas equivalent sales price of $US3.09 for every thousand cubic feet of gas (Mcfe) in the June 2012 quarter is 52 per cent weaker than the $6.41 it fetched a year ago.

It is also four per cent down on the $US3.23/Mcfe realised in the previous March quarter.

The company expects a $US3.5 million first half operating loss but might write down the value of some of its oil and gas properties,resulting in impairment provisions of $US1.5 million to $US2.5 million.

The company’s shares plunged by nearly 10 per cent on the news, down 1.5 cents to close at 14 cents.

On top of the price worries, production for the June quarter of 483 million cubic feet of gas equivalent (MMcfe) was 14 per cent below the March 2012 quarter (559 MMcfe) and 12 per cent below the 2011 June quarter (547 MMcfe).

The Australian-listed company blamed a natural decline in its operations in the Gulf of Mexico and onshore Louisiana Gulf Coast region.

Prices have recovered somewhat in the US from below $US2 a million British thermal units (MMBtu) in April to about $US3.34/MMBtu and $US3.77/MMBtu for 12-month and 36-month forward contracts last week.

The falls relate to an oversupply in North America.

Petsec’s quarterly net revenue of $1.5 million was down 57 per cent on a year ago and 16 per cent compared to the March quarter.

However, when expenses were taken into account, its EBITDAX (earnings excluding interest, taxes, depreciation, depletion, amortisation and exploration expenses) was negative $700,000 for the quarter.

It hopes September quarter production will benefit from increased production capacity at its offshore Marathon fields.

The company expects to meet its production target of two billion cubic feet equivalent of gas.

The company is also exploring for shale oil to combat the low gas price at its existing assets and in Canada.