Winter, of New York, and Millstone, of Aspen, Colorado, purchased 6.3 million registered shares in Clariant accounting for some 1.8979% of the voting rights and obtained further voting rights by entering into equity swaps through their Standard Latitude Master Fund, the SIX filings showed.

Winter and Millstone became active in Clariant when they built a 25% stake in the chemicals group together with activist investor Keith Meister's Corvex hedge fund in a successful push to halt Clariant's $20 billion merger with Huntsman in 2017.

The trio then sold their stakes in Clariant to Saudi Basic Industries Corp (SABIC) in 2018.

The sale netted them more than 30 Swiss francs ($33.89) per share, according to a person familiar with the matter. Clariant's shares traded at 13.71 francs per share on Friday.

"We have tremendous respect and admiration for SABIC and Clariant. We invest in a variety of chemical companies and our position in Clariant is a public markets investment no different than any of our others," a spokesperson for Millstone and Winter's Standard Investments said.

($1 = 0.8851 Swiss francs)

(Reporting by Brenna Hughes Neghaiwi; Editing by Sharon Singleton)