New Delhi, May 18 -- Shares of Tata Steel fell about 4% on Monday despite a robust March quarter performance, as concerns mounted over possible closure of its coke and gas plants (CGPs) in the Netherlands due to emission norm breaches.

The stock reaction was driven by regulatory risks at Tata Steel Netherlands (TSN). In April, local agencies issued a letter to TSN expressing their intention to revoke permits for its 40-50-year-old CGPs, citing non-compliance with emission norms.

While TSN could procure coke from the market if the units are shut, that would significantly dent profit margins and could render operations commercially unviable.

The regulator's move can impact the financial stability of TSN, "given the significance of the fa...