Patients with metastatic colorectal cancer will be treated with standard chemotherapy according to the investigators choice. In addition to chemotherapy, Avastin (bevacizumab) will be given during the treatment period. After the chemotherapy is finished (after 18 weeks), maintenance therapy will be given and the patients will be randomized to treatment with either with Avastin alone or Avastin in combination with Tarceva (erlotinib). Patients with progressive disease, or patients suitable to curative resection of metastases will be taken out of study.