Environment Minister Alex Attwood said the failure of a legal challenge to a draft retail planning policy means he can now clarify the law on retail development.
Central Craigavon - which owns Rushmere Shopping Centre - had asked the Court of Appeal if Mr Attwood's department needed to carry out a new environmental assessment before introducing any fresh rules on retail planning policy.
The action is connected to a bid by Central Craigavon and other parties to halt a John Lewis store and 19 linked shops at Sprucefield around 15 miles from Craigavon.
The policy, draft PPS5, includes guidelines on how retail development at Sprucefield will be handled.
Mr Attwood said yesterday's ruling would promote a "stable retail planning policy regime".
"This is good news for the future of retailing in Northern Ireland. The way though is now clear for me to settle the future of retail planning policy for Northern Ireland."
Central Craigavon's appeal queried the department's ability to take over responsibility for the policy document in January 2008 after it was transferred from the Department for Regional Development without getting clearance from the rest of the Executive.
It had been claimed that the proposed policy gives preferential status for the John Lewis development, which has been delayed by court challenges since an application for planning permission was first made by John Lewis in 2004.
Last year the High Court ruled that a decision to adopt draft PPS5 should have gone before the Stormont Executive for approval.
However, the judge yesterday refused to quash the move by the DoE.
Although Central Craigavon Ltd was deemed to have won the case, it mounted an appeal on the strategic environmental assessment issue.
Its lawyers argued that in formulating draft PPS5 the DoE had not complied with mandatory environmental assessment requirements under European or domestic law.
David Scoffield, for Central Craigavon, said the draft policy was a plan or programme on the environment which required such an assessment.
Lord Justice Girvan, sitting with Lord Justices Higgins and Coghlin, held that draft PPS5 cannot be considered a plan or programme within the relevant legislation.