Caltrain took one step closer Wednesday to becoming a faster, cleaner and quieter rail system for the Peninsula, San Francisco and the South Bay.

The Metropolitan Transportation Commission Wednesday morning approved an agreement with the California High-Speed Rail Authority and five Bay Area transit agencies to provide around $1.4 billion to upgrade and electrify the Caltrain system.

In an effort to gain support for the 800-mile high-speed train system connecting major metropolitan areas in Northern and Southern California, the CHSRA has proposed making early investments in existing local transit systems in the Bay Area and the Los Angeles basin.

One of the proposed investments is to commit more than $700 million toward the electrification of Caltrain, which could be achieved by 2020 and would help prepare the local transit corridor for the future high-speed rail system.

"It will transform our service completely," Caltrain spokesman Seamus Murphy said Wednesday. "The benefits are just tremendous."

Replacing Caltrain's heavy, diesel-powered engines with lighter, electric cars will allow the trains to run quieter, make more stops, and decrease air pollution, Murphy said.

The state's commitment to move forward with investing in local transit at high speed-rail's "bookends" -- the Bay Area and the L.A. basin -- has been met with broad support from labor and environmental groups and local elected officials, including Rep. Jackie Speier, D-San Mateo, Assemblyman Rich Gordon, D-Menlo Park, and San Carlos Mayor Andy Klein.

With its unanimous approval of the agreement, the MTC pledged to match the state's commitment by directing $500 million in Federal Transit Administration funds toward the Caltrain electrification project.

The remaining funds would come from bridge tolls, the Bay Area Air Quality Management District, and the Peninsula Corridor Joint Powers Board.

In order for the funds to be secured and the project to get under way, the agreement now needs to be approved by the CHSRA, the San Francisco

County Transportation Authority, the San Mateo County Transportation Authority, the Santa Clara Valley Transportation Authority, the City of San Jose, the City and County of San Francisco, and the Peninsula Corridor Joint Powers Board, which owns and operates Caltrain.

The state legislature would then need to appropriate its share of the money through the state budget.

Commissioners acknowledged the many steps remaining in the funding process while praising the achievements of state and local officials to get the agreement on the table.

"What we have today is a sort of base," Association of Bay Area Governments President and MTC Commissioner Mark Green said.

"This is the first block in the many building blocks that we'll have over time," he said.

South San Francisco mayor and MTC Commissioner Kevin Mullin called the approval of the agreement a "breakthrough moment."

"This is indeed a momentous day for the Peninsula," he said.

Dozens of community members spoke at today's meeting in support of the MTC's action.

Former Palo Alto Mayor and Caltrain advocate Yoriko Kishimoto applauded the MTC's efforts to fund the modernization of Caltrain while making way for a future high-speed rail system.

"We asked high-speed rail for it to be done right and why not start with the electrification of Caltrain," Kishimoto said.

"Caltrain is so central to the quality of life, clean air and economies of Peninsula cities," she said.