The proposed employee share option plan at Aer Lingus will include provisions for workers to pay for their stakes from the airline's future profits, it has emerged. Although no final agreement has been reached on the complex arrangements, various strands of the proposal are becoming clear. The share scheme, or ESOP will bring the workers' stake in the airline to 14.9 per cent equalling that of Telecom Eireann's staff before it was floated.

But unlike the ESOP at the telecoms company, no limit will be placed on the maximum share available to the trust which will manage the ESOP.

This means that workers could potentially increase their stake from 14.9 per cent after flotation.

Workers will be given the option to use £7.6 million in cash payments due to them under the Cahill rescue plan to pay for shares in the ESOP. The staff already own some 5 per cent of the airline under separate arrangements in the Cahill plan.

It is thought that staff will be given the option to decide individually whether they want to use cash due to them to pay for the shares. The value of the stake that the cash will secure is unclear because, crucially, the purchase rate has not yet been set.

The remainder of the stake is likely be paid for in the form of a bank loan to the ESOP trust and with a new profit-sharing arrangement to be introduced once the airline is floated.

The likely flotation date is still not known. Those familiar with the process say enabling legislation to sanction the initial public offering (IPO) will have to pass the Dail stage of the Oireachtas within three weeks of its resumption in October if the airline is to be floated this year.

If this happens - and analysts agree that it is by no means certain - Aer Lingus managers and those leading the process are thought to believe the stock market launch could still go ahead in November.

Nevertheless, the Minister for Public Enterprise, Ms O'Rourke, has stated that a flotation this year is unlikely.

Managers at Aer Lingus believe that if the IPO does not go ahead this year, it will not happen until next March or April.

It is thought that the poor performance of the Eircom stock is looming over the process.

However, the offering to the public will be smaller than in Eircom's case because of the small relative size of Aer Lingus.

Either way, various people familiar with the issues said the ESOP and separate discussions on the pension at Aer Lingus and on productivity-related pay at the airline will have to be finalised well before the company goes to the market.

"Those three planes will have to land together," said one person.

It is thought that discussions on the ESOP are awaiting the involvement of more senior figures at a political and trade union level. The proposals agreed last week came despite the separation of the joint SIPTU-IMPACT negotiating teams last Friday after IMPACT's executive agreed to accept membership applications from about 1,300 cabin crew who were members of SIPTU.

In a statement yesterday, IMPACT said it rejected any allegation that it poached members from SIPTU and said it "consistently abided" by ICTU procedures.

SIPTU said it was "quite surprised" by IMPACT's acceptance of cabin crew. "SIPTU clearly understood that IMPACT had accepted that an investigation would proceed and that senior counsel would do that. We will be making a complaint to ICTU on that basis."

The company discussed its pension plan separately with SIPTU and IMPACT this week following last week's development.