Indian firm Reliance Infrastructure has begun extension work on the 140km Pune-Satara highway in the Indian state of Maharashtra.

The project, worth INR19.85m ($445.3m), started with the operations of the toll collection booths and widening of the existing four-lane road to six-lanes.

Reliance Infrastructure signed a contract with the National Highway Authority of India in December last year for the project to be executed on a design, build, finance, operate and transfer basis.

The contract entails a concession period of 24 years and the widening work will be complete in the next 24 months.

The company has also started operating and maintaining the existing four-lane road and toll collection booths.

Reliance will also develop 244km of service road, build 49 grade separation structures and 58 bridges, and upgrade two existing toll plazas in the next three months.

The highway is the main corridor connecting the cities of Mumbai and Pune to southern parts of India including Bangalore and Chennai, and its extension will reduce travel time.