COMPTON (CBSLA) –The southern portion of the Los Angeles Metro Rail’s Blue Line will reopen Saturday after being closed for four months for renovations, while the northern half will be shut down through September as it undergoes its own improvements.

A $350 million project to upgrade Metro’s oldest light rail line is at its halfway point, the agency announced Monday. The Blue Line starts in Long Beach and runs north through Compton and Watts, ending in downtown L.A.

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Since late January, it has been closed from the downtown Long Beach station north to the 103rd Street/Watts Towers station.

Beginning Saturday, service will resume between the downtown Long Beach and Compton stations.

However, that same day, service will be shut down from the Compton station north to the 7th Street/Metro Center station in downtown L.A. That closure will last through September.

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Buses will be shuttling passengers between the closed stations during this time.

As part of that project, beginning on June 22, service will also be shut down for 60 days on the Expo Line track between the LATTC/Ortho Institute and the 7th St/Metro Center stations.

The project involves replacing old tracks and overhead power lines, installing new switches and repainting stations.

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For more information on the closure, click here.