Plans to build a light rail connection to Los Angeles International Airport advanced Monday with the unveiling of four potential station sites that would link to a people mover serving passenger terminals.

After years of pursuing separate transportation plans for LAX, Los Angeles World Airports and the Metropolitan Transportation Authority now are working together to develop options for a rail stop that could tie the Green Line and the planned Crenshaw Line to the nation's third-busiest airport.

"Our work over the past six months has brought us light-years from where we were before," said Paul Taylor, Metro's deputy chief executive, who noted that environmental clearances must be completed and funding secured before construction of an LAX station could begin.