This single arm study will assess the efficacy, safety and tolerability of subcutaneous methoxy polyethylene glycol-epoetin beta (C.E.R.A.) for maintenance of hemoglobin levels in pre-dialysis participants with chronic renal anemia. Participants currently receiving maintenance treatment with subcutaneous darbepoetin alfa will receive monthly subcutaneous injections of C.E.R.A. with the starting dose of 120, 200 or 360 micrograms (mcg) derived from the dose of darbepoetin alfa or epoetin alfa in the week preceding study start.