Merck & Co. said Wednesday it has resubmitted its application for a new combination cholesterol drug to the Food and Drug Administration, which rejected the experimental medication in March. The drugmaker is seeking approval for a pill that combines a generic version of Lipitor, the top-selling drug of all time, with Merck’s cholesterol medicine Zetia. The company said in a statement that the FDA judged the drug application complete and ready for review. A decision is expected in the first half of 2013. Merck’s experimental drug, still known only as MK-0653C, contains medicines that fight high cholesterol in two different ways to reduce risk of heart attack and stroke.