Reliance Industries Limited (NSE:RELIANCE), or RIL, said Thursday that it will invest $26 billion in India over three years to expand its key business areas.

Chairman Mukesh Ambani made the announcement at the annual general meeting. India's richest man told shareholders that, because Reliance's core business areas of energy production and refinement, as well as its growing telecommunications and retail businesses, impact areas of national importance, the company's planned investments will help boost India's growth. This comes at a time when foreign investments into India are falling.

"RIL is making huge investments at a time of global economic slowdown," Ambani said. "Investment in manufacturing and retail will spur growth."

India's fourth-largest company by market value has aimed to diversify beyond its core energy business, but profits haven't come easily. Its telecoms unit, Reliance Jio Infocomm, boasts India's only nationwide permits for 4G services. However, after almost three years since acquiring the permits, the division has yet to start commercial services.

Local and foreign business leaders are worried about slowdowns in segments of the country's economy, the government's failure to push through reforms that are required to bring in new investments, and tax policies they consider unfriendly for business.

But Ambani has bullish views. He announced that Jio Infocomm would more than triple its headcount from 3,000 to 10,000 in 2014. He also said Reliance's energy unit's share of natural gas output from its U.S. shale gas operations is booming, having reached more than 11 million standard cubic meters per day -- activity that has generated $616 million in revenues and $483 million in operating profit during fiscal year 2013.