The Competition Authority has ruled that Dublin's Poolbeg Incinerator project is not in breach of competition law.
The authority rejected complaints by private waste companies that Dublin City Council's commitment to supply the facility amounted to an abuse of a dominant position.
The Irish Waste Management Association, which lodged the complaint, said it will be seeking a meeting with the authority about its ruling.
The IWMA represents around 90% of Irish private waste collectors, including commercial landfill operators and waste collection companies.
The decision has been welcomed by Dublin City Council which said the IWMA had been trying to stop one of the most innovative waste management systems in Europe.
The council said the ruling states the contract did not 'breach competition law' and it has expressed delight at what Seamus Lyons, Dublin's Assistant City Manager, described as 'the rejection... of all complaints'.
Many of the IWMA complaints centred on the put or pay clause by which Dublin City Council guarantees to provide 320,000 tonnes of waste a year to the company that will operate the plant.
The authority rejected its complaints that this clause amounted to price fixing.
A spokesman for the IWMA said that the authority had rejected some of the complaints as premature and that others had been superseded by the High Court which ruled that the council could not direct waste to a particular facility.
And he said the IWMA is taking a complaint to EU on the basis that the put or pay clause amounted to state aid.
The IWMA said the CA found 'there may be future anti-competitive threats' associated with the Poolbeg facility and that 'these may be addressed' at a later date.
The IWMA adds it is continuing to examine the judgment and will be taking-up an invitation to meet with the Authority, in particular over statements that in certain areas the CA did not have enough information.
In the short-term, the Competition Authority decision is significant as the statutory agency had the powers to initiate a full investigation into the contract - raising the possibility that it could lead to a renegotiation of its terms.
Currently, the only outstanding requirement for Poolbeg is to secure a foreshore licence - something which is under the control of the Department of the Environment.