Airtricity, the Republic's largest wind energy company, has called for a cap to be placed on large energy companies when it comes to auctioning off capacity on the north-south electricity interconnector.

Airtricity had its allocation on the interconnector significantly cut in the latest auction, presided over by the Northern Ireland regulatory authorities.

The company used to be able to transport about 120 megawatts via the interconnector, but its allocation is now down to 45 megawatts.

The company rejected industry speculation that it might have difficulties serving its customer base because of the lower allocation.

The north-south interconnector is a crucial source for power coming into the Republic.

With a major shortage of generating stations in the Republic, the link with Northern Ireland has become increasingly vital to the ESB.

Mr Dermot O'Kane, chief operations officer with Airtricity Supply, said the company had 120 megawatts of power coming on stream in 2004 via four major wind farm projects located in counties Fermanagh, Donegal, Cavan and Cork.

These projects would easily replace any lost capacity via the interconnector, according to Mr O'Kane.

He said, however, that the company was increasingly concerned by the heavy presence in the auction of dominant players such as ESB and Viridian.

He claimed that both companies already had near-monopoly positions in their respective markets and giving them huge access to the interconnector only worsened this situation.

He said Airtricity was considering writing to the Northern Ireland regulator, Ofreg, and calling for a cap to be placed on the ESB and Viridian in the auction.

"A support structure needs to be put in place for renewables and competition needs to be bolstered throughout the island of Ireland," Mr O'Kane said.

"The results of the latest auction do not bode well for achieving either of these objectives," he told The Irish Times.

He said that the bidding process was increasingly expensive and this would militate against new entrants and entrench the position of the ESB in particular.