Britney Spears is to release a two-in-one fragrance.

The 30-year-old singer - who recently signed up to be a judge on The X Factor - is launching a new scent, Britney Spears Fantasy Twist, which will combine two of the singer's favorite smells.

"With Fantasy Twist, I wanted to combine two of my favorite fragrances into a sophisticated bottle, giving my fans the power to choose the scent they desire at any given moment," she told People.

The fragrance comes in a sphere-shaped bottle that twists in half and turns into two smaller containers in Britney's favorite colours, pink and blue, which enables fans to wear both together or separately. Midnight Fantasy smells of black cherries, plum and framboise, while Fantasy has a muskier scent with hints of white-chocolate orchid and jasmine petals.

Prices begin at $39.50 for the fragrance collection, which is due to hit stores in October.

Britney has sold more than one billion bottles of her perfume range in just five years, with Fantasy - her second scent, launched in 2006 - in the top three best selling fragrances of the year's first quarter.