The Tamil Nadu government has approved Rs 2,126 crore to initiate preparatory works for the western extension of the Chennai Metro, spanning 27.9 km between Poonamallee and Sunguvarchatram.

The project, to be executed by Chennai Metro Rail (CMRL), is part of a larger 52.94 km line to Parandur, the site of the proposed greenfield airport, with an overall cost pegged at Rs 15,906 crore. According to a Government Order, Rs 1,836 crore—nearly 86 percent of the sanctioned outlay will be used for land acquisition, including compensation for structures, while the rest will cover surveys and roadworks. The state will extend this support as subordinate debt to CMRL, consistent with its policy of underwriting early-stage Metro costs.

The Poonamallee–Sunguvarchatram segment, identified as the priority phase, will feature 14 elevated stations and is estimated to cost Rs 8,779 crore. The corridor will eventually link industrial and residential hubs like Chembarambakkam, Thandalam, Irungattukottai, Sriperumbudur and Sunguvarchatram, before connecting to Parandur airport. Union government clearance is awaited.