INDIANAPOLIS » Eli Lilly and Co.'s rating on $4.6 billion in long-term debt has been dropped to A1 from Aa3 at Moody's Investors Service, which cited the drugmaker's purchase of ImClone Systems. "Although the ImClone acquisition creates favorable long-term opportunities, Lilly's former Aa3 rating could no longer be supported because of higher financial leverage and rising operating risks due to patent exposures and pipeline setbacks," Michael Levesque, Moody's senior vice president, said in a statement Thursday. Lilly is likely to complete its $6.5 billion acquisition of ImClone within several days, Moody's said. A1 is the fifth-highest rating, just behind Aa3. The ratings affect the cost of borrowing. (Bloomberg)