Last week, on the recommendation of the two regulators, the Commission for Energy Regulation (CER) and its Northern counterpart, NIAER, the Minister for Communications, Marine and Natural Resources, Noel Dempsey and NI Secretary of State, Peter Hain released a joint statement delaying the expected "go live" day until November 2007.

A spokesman for CER and Sara White, deputy secretary general of Noel Dempsey's department, disputed the characterisation of the move as a "delay". The department's statement uses the term "extend".

White also dismissed suggestions that the change in expected delivery date was due to any problems in the build of a computer system to serve as a trading platform, replacing old bilateral contracts between main generators ESB and Northern Ireland's Viridian and their wholesale customers. Swiss power engineering firm ABB has the contract to design the system, working with a energy trading system developer called Navita. ABB has executed similar projects "This is not about a failure to deliver, " said White. "It's a highly complex project. It is predicated on getting all those things right. The information systems involved are groundbreaking."

Officials pointed to early framework documents which mandate the creation of a single wholesale market by the end of 2007.

Viridian said it was "disappointed" with what it called "the delay" in a statement.

"Properly implemented the all-island market has the potential to bring significant benefits to consumers, " said spokesman Robin Greer. "While it is regrettable that the July 2007 date will not be met, we recognise that a short delay may be unavoidable."

Fine Gael energy spokesman Phil Hogan said the CER needed more "political direction" and charged that the Government had no energy policy.

"It's typical of this government's failure to plan, " he said.

Ibec director of policy Danny McCoy said he was disappointed in any delay in moving the project forward. Market trials will begin on 1 July 2007.

The two regulators will hold a meeting updating interested parties on 22 August at Ofreg's offices in Belfast.