Asiana Airlines Inc., South Korea\'s No. 2 flag carrier, has been named the best airline in fuel efficiency in the country, the government said Thursday. The Ministry of Land, Transport and Maritime Affairs made the announcement, citing a test by the Korea Transportation Safety Authority on the amount of greenhouse gas emissions by Asiana Airlines and five other local carriers. Asiana Airlines and Korean Air Lines as well as four other budget carriers signed a voluntary agreement with the ministry in 2010 to reduce their greenhouse gas emissions as part of national efforts to fight climate change. The six carriers have taken a series of steps to improve overall fuel efficiency by introducing eco-friendly aircraft and reducing flight weight as well as cleaning aircraft engines on a regular basis. Last year, the carriers reduced their use of fuel by 167,000 tons worth 180 billion won (US$163 million) and cut greenhouse gas emissions by 527,000 tons, according to the ministry. \"We will consistently induce our carriers to reduce fuel to help them secure eco-friendly competitiveness,\" a ministry official said. South Korea pledged in 2009 to voluntarily cut its greenhouse gas emissions by 30 percent from business-as-usual levels by 2030, even though the country is not required to do so under any international agreement.