The group delivered another year of strong performance in 2016 and we expect that we will further improve on this in 2017 with production increasing to between 850,000-900,000 ounces at a lower all-in sustaining cost of between US$880-920 per ounce. Cash costs per ounce are also expected to decline from US$640 per ounce to between US$580-620 per ounce in 2017. We expect production to increase through the year and as such we expect a production ratio of 45:55 in terms of the first half versus the second half of the year, which will have a commensurate impact on our cost profile and our cash generation.
The further improvement in operating metrics is primarily driven by the revision to the mine plan at Buzwagi, where mining has been extended by approximately six months. This will lead to the mining of approximately 2 million tonnes more of higher grade ore during 2017 than previously planned and will drive a step up of approximately 40% in production over 2016 and a reduction in AISC of up to 30%.
At Bulyanhulu, we expect production to be in line with the previous year and AISC to reduce by up to 5%. We expect to see a reduction in cash costs, but will see an increase in sustaining capital as we invest to enhance the operation of the process plant and undertake a targeted fleet renewal programme to improve operating efficiencies amongst the older equipment within the underground fleet. We also continue to invest in underground development and in support of this will be upgrading ventilation and paste line infrastructure as we focus on creating greater flexibility underground. This investment in core infrastructure is a critical element in optimising the value delivery from this long-life, high grade asset in combination with continuing to drive cost savings and improve mining efficiencies.
North Mara performed ahead of expectations during 2016 and as a result we expect production to reduce by up to 10% during 2017 as an increased proportion of underground ore is sourced from the lower grade West Zone which will offset the impact of the increase in underground tonnes mined. The reduction in production, together with an increase in capital as we invest in the delivery of increased underground mining rates, together with open pit waste stripping will mean that AISC will increase by up to 10%.
As a result of the investments into both Bulyanhulu and North Mara outlined above we expect to see capital expenditure in 2017 of between US$210-230 million. This is comprised of approximately US$75-85 million of sustaining capital, US$120-130 million of capitalised development / stripping and US$15 million of expansion capital, made up predominantly of capitalised drilling at North Mara as we look to delineate additional resources to support a 10 year life of mine producing in excess of 300,000 ounces per annum.
As previously indicated we plan to increase our greenfield exploration spend to approximately US$25 million, as we look to build on the excellent progress made in Kenya during 2016 and we step up our exploration activity in Burkina Faso and Mali on our expanded land packages there.