NEW DELHI/MUMBAI, March 20 -- India's plan to bring its steel industry under a domestic carbon trading market has slowed after inconsistencies surfaced in emissions data collected from steel plants, forcing the government to reverify the baseline needed to set reduction targets and allocate credits, according to two steel ministry officials familiar with the matter.

The government had gathered emissions data from about 70 plants to establish this baseline. But a review found mismatches between reported emissions and fuel use or production levels at some units, while others used differing calculation methods. In some cases, steel companies also raised concerns over how emission levels were determined.

Since emission limits and credit all...