ZURICH (Reuters) - Activist investor White Tale said it would take its demands directly to Clariant's CLN.S shareholders after the chemicals maker snubbed its request for an independent strategic review and three seats on its board of directors.

The logo of Swiss specialty chemicals company Clariant is seen at the company's headquarters in Pratteln, Switzerland October 29, 2017. REUTERS/Arnd Wiegmann

White Tale last month derailed Clariant's planned $20 billion merger with U.S.-based Huntsman HUN.S, after fighting it for months on the grounds it would destroy shareholder value.

Now the investor, which recently increased its stake in Clariant to more than 20 percent to become the biggest shareholder, appears to be stepping up its fight for influence over the Swiss group.

“White Tale has been consistent in both private conversations and in our public statements about the need for a thorough, independent review of all strategic alternatives,” White Tale said in a statement on Tuesday.

“We look forward to bringing these matters to shareholders directly,” said White Tale, whose principals include hedge fund manager Keith Meister and New York investment firm 40 North’s David Winter and David Millstone.

Last week, Clariant refused to hire an outside bank to review its options, contending that White Tale wanted only to break up the company. The board offered White Tale just one possible seat on its board.

White Tale responded that it had never advocated breaking up the company “despite the false claims by Clariant”.

White Tale has suggested in the past that Clariant divest its plastics and coatings business and invest the proceeds in higher-margin operations, but the activist investor said it was keeping an open mind about what a review might find.

Clariant maintained its tough line on Tuesday while leaving the door open for more talks.

“Clariant repeats its offer for a seat in its board of directors and the offer to White Tale to sign a non-disclosure agreement, which would allow them to gain more insight,” it said in a statement.

It reiterated that it felt the review urged by White Tale would be limited to “portfolio management without strategic insights, thus intended to solicit bids for parts or the whole of Clariant.

“This intention is confirmed by the fact that White Tale has not yet presented any strategic basis for their alleged long-term interest in Clariant.”

Clariant shares, which have risen by more than half this year as the company boosted its profit margins and faced pressure from White Tale to accelerate its development, were down 0.6 percent at 1030 GMT.

Clariant announced plans on Friday for a strategic update in 2018 that would include “defining further actions such as M&A activities, short-term portfolio management options, potential returns to shareholders, a thorough review of the cost base and the pursuit of additional growth opportunities”.

Clariant’s other big shareholder group - the Bavarian families who became owners of a combined 14 percent stake when Clariant bought Germany’s Sued Chemie in 2012 - have two board seats and support Clariant’s strategy, the company has said.