The Government of the State of São Paulo, through the Secretariat of Investment Partnerships (SPI), and the concessionaire ViaQuatro, responsible for the operation of Line 4-Yellow of the São Paulo Metro, signed Amendment No. 10 to the concession contract, which guarantees the resources for the works to expand the line to the municipality of Taboão da Serra.

The extension represents an investment of R$4.04 billion (US$751 million), covering civil works along the 3.3 km stretch that will link Vila Sônia station to the planned Chácara do Jockey and Taboão da Serra stations. The project scope also includes building a new power substation, installing operational systems, and acquiring six additional trains. Completion is anticipated within 48 to 64 months. The new route will integrate with public transportation at existing bus terminals, such as Vila Sônia, São Paulo-Morumbi, Butantã, and the Taboão da Serra Terminal, as well as access points on Monsenhor Manfredo Leite Avenue and the Prof. Francisco Morato Avenue Corridor. The extension is expected to add more than 50,000 new passengers per day to rail-based public transportation.

The executed amendment confirms the extension of the concession in return for new investments to expand the metro line, with funding coming from state resources and World Bank financing, amounting to around R$3 billion (US$563 million). These resources will finance civil works, systems, underground construction, and the acquisition of trains. In addition, concessionaire ViaQuatro will contribute about R$1 billion (US$187.8 million). Given the scale of investment, the addendum extends the concession period by 20 years. Oversight and monitoring of all project phases will be carried out by ARTESP, the State Transportation Regulatory Agency.