China's Xiaomi, one of the world's fastest-growing smartphone makers, has raised $1.1 billion in a round of funding that cements its status as one of the world's most valuable private technology companies at a valuation of $45 billion. 

Investors include private equity funds All-Stars Investment, DST Global, Hopu Investment Management and Yunfeng Capital, chief executive Lei Jun said. 

The deal is one of the first high-profile scores for All-Stars, a recently established fund headed by former Morgan Stanley tech analyst Richard Ji.

It also strengthens ties between Lei and fellow tech magnate Jack Ma, the Alibaba executive chairman who invests privately through his Yunfeng Capital fund. 

Industry sales data from recent quarters show Xiaomi has risen in just three years to become the world's third biggest smartphone maker - behind only Samsung and Apple - and the latest round of investment enforces its standing as one of the world's most valuable private companies. 

At $45 billion, Xiaomi is now worth nearly three times the market capitalisation of Lenovo Group, the world's biggest PC maker, and more than quadruple the $10 billion valuation it garnered during its last financing round in 2013. 

Xiaomi's skyrocketing valuation reflects investors' belief that it will grow into a global powerhouse despite signs it is encountering intellectual property challenges outside China. 

This month sales in India were temporarily halted after Swedish telecommunciations firm Ericsson filed a patent complaint. 

Xiaomi brands itself as an Internet company that eschews traditional marketing and sells hardware at low prices as a distribution channel for its real money maker - software and services. 

It has been investing heavily in other manufacturers with the aim of building an ecosystem of Internet-connected devices and appliances to extend its reach beyond smartphones.