New Delhi, Sept. 29 -- When it comes to investing, blue-chip stocks are often associated with established companies that have built a strong track record over the years. These companies typically have a large market presence, established businesses and a history of steady performance.

There is no fixed definition of a blue-chip stock, but the term generally refers to well-established companies that lead their respective industries.

However, even among large, established businesses, improving profitability can make a difference in their financial performance.

Here are four blue-chip stocks in India that have been expanding their margins.

It is one of the world's leading steel producers. The company has a diversified presence across the...