Xiaomi didn't reveal which overseas markets will be the focus of its globalization drive, but James Yan, an analyst at International Data Corp, a global market intelligence firm, said that the company may first expand to markets in Southeast Asia later this year and then tap the European and US markets early next year.

"Although the Chinese mobile phone market is huge, it's still crucial for companies to expand to other markets if they want to be stronger and bigger," said Yan.

Yan said Barra is probably going to focus on the development of applications and software after joining Xiaomi. It's also likely that the company will hire another international executive, who will take charge of device development, he said.

Data from several Internet consultancy firms showed that Xiaomi sold more smartphones than Apple Inc in China in the second quarter of the year. Figures from IDC said that Xiaomi's ranking is still lower than Apple, but among the top 10 best sellers in China between April and June.

The fast-growing Xiaomi booked 13.27 billion yuan ($2.15 billion) in revenue for the first half, exceeding the amount it recorded for the whole of last year, which stood at 12.6 billion yuan, according to the company's financial report.

Xiaomi has won sales with its inexpensive handsets running Google's Android operating system. While Apple sells the iPhone 5 on its Chinese website starting from 5,288 yuan, Xiaomi's most expensive handset is priced at 1,699 yuan.

However, in order to conquer overseas markets, Xiaomi will still need to work on its relationship with overseas operators, analysts said.

"It also needs to hire a lot of people who can help run Xiaomi's business and offices abroad. It will be another challenge for Xiaomi's further expansion globally," said Yan.

Shen Jingting contributed to this story.