Railroad and mining company Grupo Mexico has further trimmed its stake in Mexican airport operator Grupo Aeroportuario del Pacifico to 23.6 percent, from the 24.8 percent it reported in October, according to a regulatory filing published. Grupo Mexico has sold 5,686,879 GAP shares since October, the filing with the U.S. Securities and Exchange Commission showed. The two companies have been locked in a legal battle since 2011 when Grupo Mexico said it planned to launch a tender offer for at least 30 percent of the airport operator. GAP says its bylaws limit shareholders to holding no more than 10 percent of its outstanding stock and has been trying to force Grupo Mexico to reduce its stake. (Reuters)