Tech giant Apple is "putting increasingly more energy in India" to cash in on the booming smartphone market in the country, even as global sales of the iconic iPhone grew at its slowest pace.

The California-based company, which saw total iPhone sales growing 76 per cent in the country, said it will continue to invest in markets like India in the long-term.

"India's growth, as you know, is very good. It's quickly becoming the fastest growing BRIC country. It's the third largest smartphone market in the world, behind China and the US," Apple CEO Tim Cook said on an investor call.

After years of rocketing growth, Apple reported the slowest sales ever of its market—leading iPhone for the quarter ended December 26.

It sold a record 74.8 million iPhones, but only fractionally higher than the 74.5 million in the same period last year and the slowest growth since the iconic handsets were introduced in 2007.

However, it posted a record quarterly profit with net income growing 2 per cent year-on-year at USD 18.4 billion, while revenue was also up at USD 75.9 billion.

Recently, Apple has sent an application to the Department of Industrial Policy and Promotion (DIPP) for approval for setting up retail outlets in India.

India is one of fastest growing handset markets globally and is poised to overtake the US soon.

According to research firm IDC, shipments in India grew 21.4% year-on-year to 28.3 million units in the July-September 2015 quarter.

Samsung led the tally with 24 per cent share, followed by Micromax (16.7 per cent), Intex (10.8 per cent), Lenovo Group - Lenovo and Motorola (9.5 per cent) and Lava (4.7 per cent).

Comparing India with the Chinese market, Cook said the population of India is incredibly young.

"I think of the China age being young, at 36, 37 and so 27 (median age in India) is unbelievable. Almost half the people in India are below 25. And so I see the demographics there also being incredibly great for a consumer brand and for people that really want the best products," he said.

Cook said revenues from India were up 38 per cent and in constant currency, the growth was 48 per cent.

"So it's a very rapidly expanding country. And I think the government in India is very interested in economic reforms and so forth that I think all speak to a really good business environment for the future," Cook said.