Kylie Jenner has sold a majority stake in her cosmetics company for $600-million. Picture: Instagram

Kylie Jenner has sold a majority stake in her cosmetics company for $600-million.

The 'Keeping Up With the Kardashians' star has given 51 percent of her make-up and skincare businesses to beauty giant Coty - which owns around 77 brands including Hugo Boss, Burberry, Rimmel and Max Factor - in exchange for the lump sum.

The 22-year-old make-up guru said: "I'm excited to partner with Coty to continue to reach even more fans of Kylie Cosmetics and Kylie Skin around the world.

"I look forward to continuing the creativity and ingenuity for each collection that consumers have come to expect and engaging with my fans across social media. This partnership will allow me and my team to stay focused on the creation and development of each product while building the brand into an international beauty powerhouse."

While Coty will have overall responsibility for Kylie's company, the brunette beauty will still work alongside her team to lead creative efforts and communications.  

Pierre Laubies, Coty CEO, said: "We are pleased to welcome Kylie into our organisation and family. Combining Kylie's creative vision and unparalleled consumer interest with Coty's expertise and leadership in prestige beauty products is an exciting next step in our transformation and will leverage our core strengths around fragrances, cosmetics and skincare, allowing Kylie's brands to reach their full potential."

Since the announcement, the shares in Coty have shot up by 5 per cent - even though the deal isn't expected to be close until the third quarter of fiscal year 2020.

Earlier this year, Kylie was named the world's youngest self-made billionaire by Forbes.

The reality TV star - who has 21-month-old daughter Stormi with Travis Scott - insists she "didn't expect" to be so successful when she launched her beauty business, which Forbes magazine values at at least $900-million, four years ago.

She said at the time: "I didn't expect anything. I did not foresee the future. But [the recognition] feels really good. That's a nice pat on the back."

Most of the brand's marketing is done through social media - where the brunette beauty announces product launches, previews new items and tells fans which shades she's wearing each day - to her 175 million-plus fan base across Instagram, Facebook and Twitter and Kylie believes it's been essential to her success.

The make-up mogul signed an exclusive distribution deal in November last year with beauty store chain Ulta to stock her $29 lip kits - a matte liquid lipstick and matching lip liner - into the company's 1 000-plus stores across 50 states in the US, having previously sold only online or occasionally at pop-up shops.

She launched the company in 2015.