One of the world's biggest law firms said Thursday it is separating from the Chinese firm that was part of its global network for eight years, citing changes in cybersecurity and other rules that have rattled foreign companies. The decision by Dentons follows warnings by business groups that global companies are postponing or shifting investment away from China due to concern about an expanded anti-espionage law, tighter controls on business, a data security crackdown and raids on foreign consulting firms. Dentons said it was separating from Beijing Dacheng Law Offices due to changes in cybersecurity and data protection but gave no details.