ZURICH (Reuters) – Holcim shares were indicated to open significantly higher in premarket activity on the Swiss stock exchange on Monday after the building materials giant unveiled plans to separate and list its North American business. The company’s shares were indicated 7.09% higher according to premarket information from Julius Baer. Holcim on Sunday said it will spin off 100% of its North American operations in a New York flotation which could value the business at $30 billion. The plan is to give shares to shareholders in a spin-off. The company also named Miljan Gutovic, the head of its …