Conor Murphy has given his personal assurance that a dual carriageway to improve the Londonderry to Belfast road will be built.
The Sinn Fein Regional Development Minister moved to quell fears that the proposed Derry to Dungiven road could be scrapped.
The £250m project - the biggest of its kind in Northern Ireland - was announced in December 2005. Concerns were raised last week by Derry's Chamber of Commerce that the plans had disappeared from the Assembly's plans for Northern Ireland.
But Mr Murphy said that the plans to dual the road between Derry and Belfast via Dungiven were on course.
He said: "There is no truth that the scheme has disappeared from the NI Assembly's plans for Northern Ireland from now up to 2018. The department plans to deliver this scheme during the lifetime of the proposed Investment Strategy 2008-2018."
He added: "In July, I announced the appointment of two major civil engineering consultants to progress the upgrade of the A6 from the east of Dungiven to Derry to dual carriageway standard. Currently the consultants are looking at a number of different options for the road.
"I am planning a consultation by summer 2008 to listen to people's views. After the consultation, there will be further detailed appraisal of options.
"The plan would be to announce the preferred route for the new dual carriageway in the Spring of 2009."
He added: "The dualling of the A6 between Derry and Dungiven remains a key element of the Roads Service Strategic Roads Programme."
Janice Tracey of the Chamber of Commerce in Derry said she was "absolutely delighted" with the minister's assurances.