Exhibit 99.1


                 Gastar Exploration Announces Farm-In
               of Additional Australian CBM Properties


    HOUSTON--(BUSINESS WIRE)--July 12, 2007--Gastar Exploration Ltd.
(AMEX:GST) (TSX:YGA) announced today that it has entered into a
Farm-In Agreement with Eastern Star Gas Limited ("ESG") under which
Gastar will earn a 35% working interest in the PEL 433 and adjoining
PEL 434 properties located in New South Wales ("NSW"). Under the terms
of the Farm-In Agreement, Gastar will pay the costs of a two core-hole
program and the related costs of the evaluation of the coal reservoirs
intersected by the core-holes. ESG is the operator of PEL 238 and will
serve as operator of PEL 433 and PEL 434.

    PEL 433 is located south of PEL 238 where Gastar and ESG are
developing their Gunnedah Basin Gas Project (Coal Seam Gas Joint
Venture), targeting independent certification of proved and probable
(2P) gas reserves by year-end 2007. ESG expects to commence the two
core-hole drilling program during July on PEL 433 to evaluate coal
seam gas potential. The core-holes will evaluate the coal seam gas
potential of the Hoskissons Coal Seam within the Late Permian Black
Jack Coal Measures.

    Coal evaluation core hole drilling completed during the 1970s and
1980s by the NSW Government has already identified the distribution
and thickness of the coal measures within PEL 433. The Hoskissons Coal
Seam is believed to be thick (approximately 6 meters) and widely
distributed within the eastern part of PEL 433. However, there has
been no previous coal seam gas exploration and evaluation work in the
area, and thus there is no information on gas content, gas composition
or coal permeability. The aim of the PEL 433 core-hole program is to
gather this additional information to evaluate the potential coal seam
gas resource in the area.

    The most prospective coal seam gas area within PEL 433 underlies
the Central Ranges Natural Gas Pipeline that links Dubbo with Tamworth
and joins with the larger Moomba-Sydney Gas Pipeline. This gas
pipeline would enable gas sales within the region and potentially to
Sydney and surrounding markets.

    J. Russell Porter, Gastar's President & CEO, stated, "The addition
of these two properties is a logical extension of our joint venture
activities on PEL 238. This agreement aligns both parties' joint
venture interests within PEL 238, PEL 433 and PEL 434 for coal seam
gas development in the Gunnedah Basin. Eastern Star Gas has done an
excellent job of drilling and testing the PEL 238 pilots, and we are
excited to join them on these licenses. Based on the known extent and
thickness of the coals on PEL 433, we believe there is significant
gross reserve potential on the license."

    Gastar Exploration Ltd. is an exploration and production company
focused on finding and developing natural gas assets in North America
and Australia. The Company pursues a balanced strategy combining
select higher risk, deep natural gas exploration prospects with lower
risk coal bed methane (CBM) development. The Company owns and operates
exploration and development acreage in the Deep Bossier gas play of
East Texas. Gastar's CBM activities are conducted within the Powder
River Basin of Wyoming and upon the approximate 3.0 million gross
acres controlled by Gastar and its joint development partners in
Australia's Gunnedah Basin (PEL 238) and Gippsland Basin (EL 4416)
located in New South Wales and Victoria, respectively.

    Safe Harbor Statement and Disclaimer:

    This Press Release includes "forward-looking statements" within
the meaning of Section 27A of the Securities Act of 1933 and Section
21E of the Securities Act of 1934. A statement identified by the words
"expects," "projects," "plans," and certain of the other foregoing
statements may be deemed forward-looking statements. Although Gastar
believes that the expectations reflected in such forward-looking
statements are reasonable, these statements involve risks and
uncertainties that may cause actual future activities and results to
be materially different from those suggested or described in this
press release. These include risks inherent in the drilling of natural
gas and oil wells, including risks of fire, explosion, blowout, pipe
failure, casing collapse, unusual or unexpected formation pressures,
environmental hazards, and other operating and production risks
inherent in natural gas and oil drilling and production activities,
which may temporarily or permanently reduce production or cause
initial production or test results to not be indicative of future well
performance or delay the timing of sales or completion of drilling
operations; risks with respect to oil and natural gas prices, a
material decline in which could cause the Company to delay or suspend
planned drilling operations or reduce production levels; and risks
relating to the availability of capital to fund drilling operations
that can be adversely affected by adverse drilling results, production
declines and declines in natural gas and oil prices and other risk
factors described in the Company's Annual Report on Form 10-K, as
filed on March 27, 2007, with the United States Securities and
Exchange Commission at www.sec.gov and on the System for Electronic
Document Analysis and Retrieval (SEDAR) at www.sedar.com.

    The American Stock Exchange and Toronto Stock Exchange have not
reviewed and do not accept responsibility for the adequacy or accuracy
                           of this release.


    CONTACT: Gastar Exploration, Ltd.
             J. Russell Porter, rporter@gastar.com
             Michael A. Gerlich, mgerlich@gastar.com
             713-739-1800
             FAX: 713-739-0458
             www.gastar.com