Coca-Cola Company said it was banned from another college campus this month when the University of Michigan halted purchases of the company's products following concerns about the soft drink maker's labor practices in Colombia and environmental actions in India. The move by UMich, which has more than 40,000 students, follows a similar ban earlier this month by New York University, which has more than 50,000 students. The two are among Coke's biggest university accounts.