The Obama administration is likely to block a proposed $15 a share buyout offer by U.S. pharmacy services provider Omnicare Inc (OCR.N) for smaller rival PharMerica Corp (PMC.N), New York Post reported on Thursday, citing a source close to the matter. A decision from the Federal Trade Commission on the deal is expected by the end of next week, the paper said, citing the source. The newspaper quoted the source as saying "the FTC is not offering Omnicare any remedies," which it said indicated it is not trying to find a way to approve the deal.