Gastar Exploration Announces 138% Increase in Proved Reserves and Provides 2012 Capital Budget and First Quarter Production Guidance

Gastar Exploration Ltd. GST today announced its total proved Securities Exchange Commission reserves as of December 31, 2011 and approved its 2012 capital budget. Proved Reserves Gastar reported year-end 2011 proved natural gas, oil and condensate and natural gas liquids (NGLs) reserves of 119.7 Bcfe estimated in accordance with SEC regulations. This represents an increase of 138% over year-end 2010 proved reserves of 50.3 Bcfe. Of the 119.7 Bcfe, 76.6% were attributable to natural gas, 9.6% to oil and condensate and 13.8% to NGLs. The pre-tax present value discounted at 10% ("PV-10") of the estimated proved reserves increased to $217.1 million from $67.3 million at year-end 2010. The Appalachian Basin represented 70% of proved reserve volumes and 80% of the PV-10 value with East Texas comprising the majority of the remainder of proved reserves and PV-10 value. Proved undeveloped reserves at year-end 2011 represented approximately 34% of total proved reserves compared to approximately 17% at year-end 2010. Proved undeveloped reserves at year-end 2011 were comprised of 41.2 Bcfe of Appalachia Basin reserves having a PV-10 value of $67.3 million.