Two Different Treatments 24 vs 48 Weeks Chronic Hepatitis C Genotypes 2 and/or 3 in co-Infected HIV-HCV

Inclusion Criteria: * Male and female patients of 18-65 years of age * Serologic evidence of chronic hepatitis C infection by detectable plasma HCV-RNA * Serologic evidence of HIV-1 infection by ELISA and Western-blot * Stable status of HIV-1 infection in the opinion of the investigator * Negative urine or blood pregnancy test (for women of childbearing potential) documented within the 24-hour period prior to the first dose of study drug. Additionally, all fertile males and females must be using two forms of effective contraception during treatment and during the 6 months after treatment end. This may include, but is not limited to, using birth control pills, IUDs, condoms, diaphragms, or implants, being surgically sterilized, or being in a post-menopausal state. * Willingness to give written informed consent and willingness to participate to and comply with the study Exclusion Criteria: * Women with ongoing pregnancy or breast feeding * IFN or ribavirin therapy at any previous time * Any investigational drug \<6 weeks prior to the first dose of study drug * History or other evidence of a medical condition associated with chronic liver disease other than HCV * Hepatocarcinoma observed * History or other evidence of bleeding from esophageal varices or other conditions consistent with decompensated liver disease * Active HIV-related opportunistic infection and/or malignancy requiring acute systemic therapy * Absolute neutrophil count \<1500 cells/mm3 * Hgb \<12 g/dL in women or 13 g/dL in men or any patient for whom anemia would be medically problematic * Hemoglobinopathy (e.g. thalassemia) or any other cause of or tendency for hemolysis * Platelet count \<90000 cells/mm3 * Serum creatinine level \>1.5 times the upper limit of normal at screening * History of severe psychiatric disease, especially depression. Severe psychiatric disease is defined as treatment with an antidepressant medication or a major tranquilizer at therapeutic doses for major depression or psychosis, respectively, for at least 3 months at any previous time or any history of the following: a suicidal attempt, hospitalization for psychiatric disease, or a period of disability due to a psychiatric disease * History of a severe seizure disorder or current anticonvulsant use * History of immunologically mediated disease (e.g., inflammatory bowel disease, idiopathic thrombocytopenic purpura, lupus erythematosus, autoimmune hemolytic anemia, scleroderma, severe psoriasis, rheumatoid arthritis) * History or other evidence of chronic pulmonary disease associated with functional limitation * History of significant cardiac disease that could be worsened by acute anemia * History of thyroid disease poorly controlled on prescribed medications. Patients with elevated thyroid stimulating hormone (TSH) concentrations with elevation of antibodies to thyroid peroxidase and any clinical manifestations of thyroid disease are excluded * Evidence of severe retinopathy * History of major organ transplantation with an existing functional graft * History or other evidence of severe illness, malignancy or any other conditions which would make the patient, in the opinion of the investigator, unsuitable for the study * History of any systemic anti-neoplastic or immunomodulatory treatment (including supraphysiologic doses of steroids and radiation) \<6 months prior to the first dose of study drug or the expectation that such treatment will be needed at any time during the study * Drug use within 6 months of 1st dose and excessive alcohol consumption