Wal-Mart Stores (WMT) increased the share employees pay for its medical coverage programs 8% to 36%, depending on hours worked and pay, saying it expects health costs to continue rising .

Like other large employers, Wal-Mart is trying to manage costs while at the same time preparing to meet strict rules mandated in President Obama's health care overhaul, commonly called ObamaCare.

Wal-Mart, the world's largest private employer with some 1.4 million employees globally, said in a mailing to employees that for its most popular plan, which covers individuals, the bi-weekly paycheck deduction would increase 13% to 23%, or $2 to $11 per paycheck.