Moody's pushed state power firm Eskom's credit rating deeper into subinvestment territory on Tuesday, saying a government plan to reorganise the cash-strapped South Africa n firm would be hard to implement without explicit support from the cabinet. Moody's cut Eskom's long-term corporate family rating, or unguaranteed debt, to B2 from B3, six notches below the investment-grade level, with a negative outlook. The rating firm also cut the power company's zero-coupon eurobonds to B2 from B3. The agency on Friday kept South Africa 's sovereign debt at Baa3, the lowest rung of investment grade, but revised the outlook on that rating to "negative".