SABIC's move to become Clariant's largest shareholder has prompted speculation that the Saudi company could increase its holding, but Clariant CEO Hariolf Kottmann said SABIC had no current plans to make a full bid.

"If they change their position, they will let us know," Kottmann said, adding any talk of such a deal was premature, especially before the two have had detailed talks.

Kottmann told Reuters on Wednesday after Clariant published first-half results that the timing of the strategy update with investors, planned for early September, was now uncertain.

The Saudi chemicals company bought a quarter of Clariant in January, helping to resolve the Swiss company's fight with activist investors who had blocked its planned merger with rival Huntsman.

But the Swiss company cannot start in-depth talks with SABIC over their future, Kottmann said, until regulators in countries including Brazil and Mexico give their blessing to SABIC's purchase of the stake.

"If we receive the antitrust clearance at the beginning of September...we need at least four, five, six weeks to continue the discussions we've had currently, to bring a bit more meat to the bone," Kottmann said.

He said lawyers from both sides have said there was no reason not to get the clearance, but the formal process is taking more time.

Clariant shares were down 1.8 percent at 1055 GMT.

TAKEOVER TALK

SABIC's purchase has triggered speculation about a full takeover of Clariant.

"Clariant remains the top takeover candidate in the sector," Baader Helvea analyst Markus Mayer said.

But Kottmann said that SABIC had not changed its tone since January, when it said it had no current plans to launch a full takeover.

"From today's point of view, it (a takeover) makes no sense, because I think now we are in a much earlier stage and phase of discussions where we have the obligation to find value-creating potentials for our shareholders," Kottmann said.

Clariant's first-half net income rose to 211 million Swiss francs ($212 million), up from 153 million francs a year ago.

Sales rose 8 percent to 3.4 billion francs, from 3.1 billion francs in the same period in 2017 and ahead of analyst forecasts in a Reuters poll.

Zuercher Kantonalbank analysts said a drop in profitability at Clariant's natural resources business that supplies the oil and mining industries showed it was taking longer to recover than expected. The EBITDA margin at this business fell to 12.6 percent in the first half, down from 14.6 percent

Clariant Chief Financial Officer Patrick Jany said natural resources was one of the areas where the company's business is slated to improve in the second half.

(Reporting by John Miller. Editing by Jane Merriman)