Inclusion Criteria:

- Adult patients, >/= 18 years of age

- CD20-positive indolent B-cell non-Hodgkin's lymphoma (follicular lymphoma or splenic,
nodal or extranodal marginal zone lymphoma)

- Stage III or IV disease, or Stage II bulky disease (defined as tumour diameter >/= 7
cm), requiring treatment

- For patients with follicular lymphoma: requirement for treatment according to GELF
criteria

- For patients with symptomatic marginal zone lymphoma: disease that is de novo or has
relapsed following local therapy (i.e. surgery or radiotherapy) and requires therapy
as assessed by the investigator

- At least one bi-dimensionally measurable lesion (>2 cm in its largest dimension by CT
scan or MRI)

- Eastern Cooperative Oncology Group (ECOG) performance status 0, 1 or 2

- Adequate hematologic function

Exclusion Criteria:

- Central nervous system lymphoma, leptomeningeal lymphoma, or histological evidence of
transformation to a high-grade or diffuse large B-cell lymphoma

- Grade 3b follicular lymphoma, small lymphocytic lymphoma or Waldenström's
macroglobulinaemia

- Ann Arbor Stage I disease

- History of severe allergic or anaphylactic reactions to monoclonal antibody therapy,
known hypersensitivity to any of the study drugs or sensitivity to murine products,
or history of sensitivity to mannitol

- For patients with follicular lymphoma: prior treatment for non-Hodgkin's lymphoma
with chemotherapy, immunotherapy, or radiotherapy

- For patients with non-follicular lymphoma: prior treatment with chemotherapy or
immunotherapy

- Regular treatment with corticosteroids during the 4 weeks prior to the start of Cycle
1

- Evidence of significant, uncontrolled concomitant diseases that could affect
compliance with the protocol or interpretation of results

- For patients who will be receiving CHOP: LVEF <50% by MUGA scan or echocardiogram

- History of prior malignancy with the exception of curatively treated basal or
squamous cell carcinoma of the skin and low-grade in situ carcinoma of the cervix

- Known active infection, or major episode of infection within 4 week prior to the
start of Cycle 1

- Vaccination with a live vaccine within 28 days prior to randomization

- Recent major surgery (within 4 weeks prior to start of Cycle 1), other than for
diagnosis

- Abnormal laboratory values as defined by protocol for creatinine, creatinine
clearance, AST or ALT, total bilirubin, INR, PTT or aPPT, unless these abnormalities
are due to underlying lymphoma

- Positive as per protocol definition for HIV, HTLV1, hepatitis C or chronic hepatitis
B

- Pregnant or lactating women

- Life expectancy < 12 months

- Participation in another clinical trial with drug intervention within 28 days prior
to start of Cycle 1 and during study