The contract between the Railway Procurement Agency (RPA) and the British company hired to run Dublin's Luas light railway system was performance-related, the Taoiseach told the Dáil.
Mr Ahern said that its UK operation had been subject to controversy because the Strategic Rail Authority had withdrawn the company's licence for heavy rail operations. He added that the RPA had set specifications relating to quantity, quality, output and performance.
"There are tight restrictions, penalties and bonuses, as well as opt-out clauses," he added. He said that the company, known as Connex, would collect fares on the RPA's behalf and these would be set against an agreed fee. Should revenues fall short of the contract sum, the balance would be paid by the RPA, conditional on Connex's performance.
"The contract includes penalty clauses for failure to meet targets and bonuses for exceeding them," said Mr Ahern. "It was signed in May 2002 and it will be binding for five years from the commencement of the operations."
Mr Ahern, who was replying to the Green Party leader, Mr Trevor Sargent, said that Connex was part of a large international conglomerate within the Veolia group and it operated heavy and light rail systems and bus services in more than 100 locations throughout the world, including France, Germany, Sweden, the US and Australia.
The Taoiseach also said the two lines were of the same gauge and that trains from the two lines would be interchangeable.