Chemotherapy and bevacizumab is given for 4 months. Patients who have not progressed will continue with maintenance treatment with either bevacizumab (Avastin) alone, or bevacizumab and erlotinib (Tarceva).

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.

Inclusion Criteria:

1. Adenocarcinoma of the colon or rectum.
2. Age > 18.
3. Measurable disease according to RECIST criteria.
4. Expected survival more than three months.
5. Adequate bone marrow, liver and kidney function.
6. INR < 1.5 times upper limit.
7. Adequate contraception for fertile patients.
8. Signed written informed consent.

Exclusion Criteria:

1. Earlier chemotherapy for metastatic colorectal cancer.
2. Adjuvant treatment within 6 months.
3. Surgery or significant trauma within 28 days prior to study entry.
4. Planned radiotherapy against target lesions.
5. CNS metastases.
6. Prior malignancy within 5 years except ca in situ of cervix and basal cell carcinoma.
7. Bleeding diathesis
8. Uncontrolled hypertension.
9. Significant cardiovascular disease.
10. Treatment with anticoagulant drugs.
11. Participation in other clinical trial.
12. Pregnant or lactating.