lariant AG's bid to create a $14 billion chemicals giant through a merger with U.S.-based Huntsman Corp. has come under attack from a group of the Swiss company's largest shareholders who are pushing to derail the transaction. In a filing with Swiss regulators, 40 North Latitude Master Fund Ltd., controlled by U.S. investors David Winter and David Millstone, and Corvex Master Fund Ltd, controlled by investor Keith Meister, disclosed that their stake in Clariant exceeded 5% of voting rights. "We have noticed the increased investment of Corvex / 40 North in Clariant and their demands," a Clariant spokesman said in a statement. "We are taking all of our shareholders' interests seriously and maintain our long-practiced open and engaging attitude with them. In that spirit we are in contact with Corvex / 40 North." Clariant shares rose 2.8% in early trading Tuesday on the news. The two companies said in May that they had agreed to an all-share deal as the industry seeks ways to cut costs and boost revenue. Based on the companies' values at the time of the announcement, Clariant shareholders would own about 52% of the new entity, with Huntsman investors owning the rest. A combination would create a trans-Atlantic company valued at about $20 billion including debt, offering an array of chemicals such as polyurethanes, pigments, automotive fluids, additives and resins that are used across industries ranging from aerospace to agriculture to household-cleaning. Together Huntsman, which is based in Woodlands, Texas, and its Swiss-based rival would operate in well over 100 countries and employ about 32,000.via