A potential merger on the cards between Swiss cement maker Holcim,Ambuja Cements

Holcim Ltd., the world's biggest cement maker, is considering a potential sale of businesses in India including Ambuja Cements Ltd., according to people familiar with the matter.

The Swiss giant is gauging interest in its controlling stake in Ambuja, the people said, asking not to be identified as the information is private. Holcim controls 63.1% of Ambuja, which has a market value of about $9.6 billion.

Deliberations are in the early stages and may not lead to a transaction, the people said. Shares of Ambuja have gained more than 20% this month, partially fueled by market speculation about a potential merger.

A representative for Holcim declined to comment, while a spokesperson for Ambuja couldn't immediately be reached for comment outside regular business hours in Mumbai.

Holcim has been selling off non-core assets to reduce debt and diversify through acquisitions. It divested its Brazilian unit for $1 billion in September and is also planning to sell its business in Zimbabwe.

Meanwhile, the company agreed to buy Malarkey Roofing Products in December and Firestone Building Products in early 2021, as Chief Executive Officer Jan Jenisch adds new construction businesses outside of traditional cement.

Founded in 1983, Ambuja has a cement capacity of 31 million metric tons, and has six integrated manufacturing plants and eight cement grinding units in India, its website shows. Its subsidiaries include ACC Ltd., which is also publicly traded.