The General Secretary of the Congress of Trade Unions, David Begg, has said the six-week target for agreement on a new national pay deal may have been 'optimistic'.
Mr Begg was speaking after talks at Government Buildings broke up after over an hour.
Unions and employers have blamed each other for the lack of progress on the key issue of employment standards.
Turlough O'Sullivan of IBEC said claims of worker exploitation and jobs displacement had been exaggerated.
However, the President of SIPTU, Jack O'Connor, said the delay was due to the failure of employers to engage on the issue.
A series of bilateral talks are to take place next week.
The talks had been scheduled to conclude in about three weeks' time.
However, It is understood significant gaps remain between the demands of unions and employers, which may result in Government officials intervening to draw up compromise proposals.
The Irish Congress of Trade Unions is demanding new legislation to protect employment standards and prevent job displacement.
Employer bodies are strongly resisting the introduction of any extra regulation, conceding however that greater enforcement of existing labour law is needed.
The Irish Business and Employers Confederation has also dismissed union concerns about job displacement, saying a number of recent surveys had proved these concerns to be unfounded.
However ICTU has said there is evidence of downward pressure on wages in certain sectors where migrant labour is increasing. It wants a new legal framework to ensure workers could not be paid less than the 'going rate' for a job.
IBEC says this would effectively introduce another tier of the minimum wage. The employers' body is also calling for changes to legislation used by non-unionised workers.
