REC-T-142 Block (Gran Tierra Energy 70% WI & Operator, Alvorada 30% WI)Drilling of the first horizontal sidetrack well, currently planned to be drilled from the 1-GTE-01-BA pilot hole, has been delayed to June, 2012 due to rig availability. This will be the first of three horizontal sidetrack wells that Gran Tierra Energy expects to be drilled to test the productivity of the light oil sandstone reservoir targets in the Recôncavo Basin. Production First quarter production and sales have been impacted by approximately 26 days of oil delivery restrictions due to three separate Ecopetrol-operated Oleoducto Transandino (" OTA") pipeline disruptions in Colombia, the latest of which occurred on March 13, 2012. Gran Tierra Energy continued production at a reduced rate while the OTA pipeline was down, selling a portion of its crude through trucking and storing excess crude. The pipeline has been repaired and was back in service on March 24, 2012. Gran Tierra Energy's current production is approximately 19,200 barrels of oil equivalent per day (" BOEPD"). Also, as a result of entering into new crude oil sales and transportation agreements with Ecopetrol as of February 1, 2012, which changed the sales point of produced oil from Orito to Tumaco, Gran Tierra Energy's reported crude oil inventory will increase representing ownership of oil in the OTA and associated Ecopetrol owned facilities. This change in sales point and the increase in crude oil inventory will have a corresponding one-time reduction in oil sales of approximately 1,600 BOEPD net after royalty (" NAR") to be reported for the quarter. As a result of the OTA pipeline disruptions and the new crude oil sales and transportation agreements, sales for all Gran Tierra Energy properties are expected to average approximately 16,000 BOEPD NAR, from January 1, 2012 to March 31, 2012. About Gran Tierra Energy Inc. Gran Tierra Energy is an international oil and gas exploration and production company, headquartered in Calgary, Canada, incorporated in the United States, trading on the NYSE Amex Exchange (GTE) and the Toronto Stock Exchange (GTE), and operating in South America. Gran Tierra Energy holds interests in producing and prospective properties in Colombia, Argentina, Peru, and Brazil. Gran Tierra Energy has a strategy that focuses on establishing a portfolio of producing properties, plus production enhancement and exploration opportunities to provide a base for future growth. Gran Tierra Energy's Securities and Exchange Commission filings are available on a web site maintained by the Securities and Exchange Commission at http://www.sec.gov and on SEDAR at http://www.sedar.com. Forward Looking Statements and Advisories This news release contains certain forward-looking information and forward-looking statements (collectively, "forward-looking statements") under the meaning of applicable securities laws, including Canadian Securities Administrators' National Instrument 51-102 - Continuous Disclosure Obligations and the United States Private Securities Litigation Reform Act of 1995. The use of the words "expected", "planned", "scheduled", "will" and derivations thereof and similar terms identify forward-looking statements. In particular, but without limiting the foregoing, this news release contains forward-looking statements regarding Gran Tierra Energy's planned and expected drilling operations in Argentina, Brazil and Colombia including, without limitation, anticipated production, drilling and testing timelines. The forward-looking statements contained in this news release reflect several material factors and expectations and assumptions of Gran Tierra Energy including, without limitation: assumptions relating to log evaluations; that Gran Tierra Energy will continue to conduct its operations in a manner consistent with past operations; the accuracy of testing and production results and seismic data; the effects of certain drilling techniques; and the general continuance of current or, where applicable, assumed operational, regulatory and industry conditions. Gran Tierra Energy believes the material factors, expectations and assumptions reflected in the forward-looking statements are reasonable at this time but no assurance can be given that these factors, expectations and assumptions will prove to be correct.