The NHS Commissioning Board is the organisation that will performance manage GP consortia and hold GP contracts under the government's NHS reform plans.
A DoH spokesman said: 'Our intention is that David Nicholson will fill both roles at first and he will cease being the chief executive of the NHS completely on 31 March 2012.
'We are also planning to appoint the chairman of the NHS Commissioning Board during 2011/12 to oversee its operations.'
In a letter to NHS organisations in December, Sir David said that the NHS reform plans were 'perhaps the most significant and complex that the NHS has faced'.
The DoH is yet to decide whether it will appoint a replacement to fill the NHS chief executive post after Sir David's departure.
Meanwhile, former DoH national clinical director of primary care for England Dr David Colin-Thome has called for GP consortia to shift more NHS work into community settings and reinvest savings in primary care.
Dr Colin-Thome has quit the DoH and become a patron of the Family Doctor Association.