Lei Jun, founder and CEO of China's mobile company Xiaomi, speaks in front of a chart showing Xiaomi Phone's sales volume (R) and sales amount (L) at a launch ceremony of Xiaomi Phone 4, in Beijing, July 22, 2014. [Photo / Agencies]

Esther Woo, chief operating officer for All-Stars Investment, declined to comment. Leonid Solovyev, a spokesman for DST, could not immediately be reached for comment. GIC declined to comment in a text message.

Xiaomi's revenue is set to more than double this year to exceed $12 billion, according to estimates from Neil Shah, Mumbai-based research director for devices at Counterpoint Research.

At $45 billion, Xiaomi would be valued at 3.75 times sales of Shah's estimate for this year. That is higher than any publicly traded personal-computer or mobile-phone maker, according to data compiled by Bloomberg. Apple trades at 3.73 times sales.

Xiaomi does not make its own devices and relies on contract manufacturers, including FIH Mobile Ltd and Inventec Corp, to build them. The company also sells to consumers from its website to keep costs down.

Xiaomi more than tripled global smartphone shipments to 17.3 million units in the third quarter, from 5.6 million a year earlier, International Data Corp reported on Oct 29. Its market share more than doubled to 5.3 percent from 2.1 percent.

The $1 billion fundraising was reported earlier by the Wall Street Journal.

Analysys International, a Chinese research company, said Xiaomi is set to overtake Samsung Electronics Co in China by the end of 2014. The company is to unveil its next-generation flagship device in January.

Gao Yuan contributed to the story.