Xiaomi, the Chinese technology company tipped to be bigger than Apple and Samsung, has raised $1.1bn (£700m) in its latest round of funding, taking its valuation to $45bn.
This staggering figure makes Xiaomi, which is almost completely unheard of in the West, one of the most valuable privately-owned companies in the world.
Chief executive officer Bin Lin shared the news on his Facebook page, describing the funding round as "an affirmation of Xiaomi's stellar results in four years, and heralds a new phase for the company."
Lin added: "We will strive to continue bringing innovation to everyone, with a goal of producing high-quality, high-performance devices with great user experience. In January 2015, we will be unveiling our next flagship device. Big thanks to all Mi fans, business partners and investors for your strong support."
Based in Beijing, Xiaomi is the world's fourth largest smartphone maker, behind Samsung, Apple and Lenovo, which only inherited third place in October when it completed its acquisition of Motorola Mobility from Google.
Xiaomi's new valuation is three times larger than Lenovo's $14.5bn market cap. It is also worth more than taxi app company Uber, which reached a valuation of $41bn earlier this month.
Xiaomi's first funding round saw it raise $41m in December 2010, followed by a further $90m a year later and $216m in the summer of 2012. Its third funding round saw the company valued at $10bn last August.
Not currently selling phones outside of its native China, Xiaomi shifted 1.16 million handsets on Singles Day - 11 November, the Chinese answer to Black Friday - raising £160m in sales in 24 hours. The company aims to sell 60 million smartphones in 2014, tripling the number of handsets shipped in 2013, and 2015 will see it enter new territories, starting in Brazil.