India, Sept. 15 -- Highway developers in India typically operate through project-specific special purpose vehicles set up under a parent promoter, a structure meant to ring-fence risk on any single concession from the rest of the group's business. That separation works until the regulator decides to pierce it, holding the promoter itself accountable for a concessionaire's conduct rather than just the SPV or its site staff. PNC Infratech's latest disclosure to exchanges shows exactly that kind of escalation playing out.

Shares of PNC Infratech Ltd. were trading at Rs. 140.32, down 20 percent from previous close of Rs. 175.40. The stock opened at Rs. 165.00, reaching an intraday high of Rs. 165.50 and low of Rs. 140.32. The company curren...