Coal-mining companies whose stock prices have tumbled could use some friends. Instead, they have become the target of campaigners hoping to cast the sector as the new Big Tobacco. With a meeting of global leaders to discuss climate change beginning Monday in Paris, the campaign has been building support. This week, German insurer Allianz SE , ALIZF 2.16 % which manages roughly $2.1 trillion in assets, said it would no longer invest in mining companies or utilities that generate more than 30% of their sales or energy output from coal. Allianz has about $4.25 billion invested in coal, mostly in bonds, and will gradually exit from the sector over coming months as they mature. Two years of talks on coal with several nongovernmental organizations, including Transparency International, WWF and Germanwatch, influenced the money manager’s final call, although Chief Executive Oliver Bäte said Allianz is also aware of efforts to […]