The Ranbaxy deal, which closed on Tuesday, was the largest acquisition in the pharmaceutical industry in Asia in 2014, and the biggest ever for Sun Pharma.
Managing Director Dilip Shanghvi, who founded Sun Pharma and is one of the country's richest men, said on Wednesday the Ranbaxy deal would not stop him from pursuing other big-ticket acquisitions.
He declined to comment on how much he would be willing to spend.
With Ranbaxy in its fold, Sun Pharma's market share in India alone is at nearly 10 percent. About 40 percent of the turnover of the combined company comes from India and other emerging markets, and it has 45 manufacturing plants that make products for sale across 150 countries.
Shanghvi said winning back the confidence of regulators would be the company's "most important focus", as it works to resolve quality control issues that have led to U.S. import bans on all of Ranbaxy's India drug manufacturing plants.
The U.S. Food and Drug Administration is stepping up scrutiny of India's pharmaceutical industry, which supplies nearly 40 percent of the drugs sold in the United States. Shanghvi also said Sun Pharma was looking to increase its annual research spending to about $300 million from $250 million now, without saying when research spending would rise.
The increase would be mainly focused on tildrakizumab, a psoriasis drug Sun Pharma is developing under a licensing deal it struck with U.S. firm Merck & Co Inc in September.
Sun Pharma is keen to do more such licensing deals with large pharmaceutical firms that are looking at emerging markets such as India to license out their products, Chief Financial Officer Uday Baldota told Reuters at a recent meeting.
"Ranbaxy is three times our size in the emerging world. So, to that extent, we become four times more attractive," he said. Shanghvi, who made a $290 million personal investment for a 23 percent stake in wind turbine maker Suzlon Energy Ltd last month, said his focus continues to be on making Sun Pharma a successful business.
"Every investment I have made outside of Sun is financial, I have no interest in running those businesses."
(Additional reporting by Aman Shah in Mumbai)
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