MUMBAI, Nov. 9 -- The closing auction session (CAS) has contributed to a widening earnings divide between India's equity and commodity exchanges, weighing on profits at the former while the latter has continued to grow.

In the July-September quarter, the National Stock Exchange (NSE) and BSE reported sequential declines in profit as trading activity came under pressure. The Multi Commodity Exchange (MCX), by contrast, benefited from heightened activity in gold and silver, extending its earnings growth.

The outlook for the three exchanges, however, could shift. With the Securities and Exchange Board of India (Sebi) rolling back CAS and restoring the earlier settlement mechanism, trading volumes could recover at equity exchanges, lifting ...