MILAN, March 22 (Reuters) - Italian fashion house Valentino said on Friday it had agreed with its creative director Pierpaolo Piccioli to end their collaboration, adding that a new "creative organisation" would be announced soon.

Piccioli started working at Valentino in 1999 and took on the role of sole creative director in 2016.

"We extend our deepest gratitude to Pierpaolo for writing an important chapter in the history of the Maison Valentino. His contribution over the past 25 years will leave an indelible mark," Valentino's chairman Rachid Mohamed Rachid said.

Piccioli said in the same statement: "I've been in this company for 25 years, and for 25 years I've existed and I've lived with the people who have woven the weaves of this beautiful story that is mine and ours."

French luxury group Kering bought a 30% stake in Valentino last year from Qatari investment fund Mayhoola for 1.7 billion euros ($1.84 billion).

The agreement includes an option for Kering to purchase the whole of Valentino's share capital no later than 2028. ($1 = 0.9246 euros) (Reporting by Elisa Anzolin, Editing by Gavin Jones and Alison Williams)