Eircom deputy chairman, Mr Con Scanlon, is to resign as general secretary of the Communications Workers' Union (CWU), it emerged last night.

In a statement, the union said that Mr Scanlon had decided to step down from his post in three months. The CWU did not give a reason for his departure and efforts to contact him last night were unsuccessful.

Mr Scanlon represents the employee share option trust (ESOT) on the recently re-floated Eircom's board. As the company's biggest union, the CWU dominates the ESOT's membership.

Over the next 10 years, he is to get pension payments from Eircom worth €1 million. He has also received a lump sum of €230,000 from the company. At flotation he earned €560,000 on his shares and is entitled to yearly director's fees of €106,000.

The ESOT, in which he played a central role in creating in 1998, has a stake in the company valued at more than €340 million.

Its members shared a €66 million payout, an average of €4,551 each, when the telecoms company was refloated last month. The windfall came from the sale of preference shares.

The trust's decision to support the Sir Anthony O'Reilly-led Valentia consortium was key to its success in taking the company private at the end of 2001.

A number of tax changes were necessary to ensure its participation in the consortium.

The 450,000 small shareholders who bought Telecom Éireann shares when it was floated in 1999 lost heavily on the Valentia take-private deal.

Mr Scanlon is 50 years old and became the first general secretary of the CWU when it was formed in 1997 from the merger of two other unions, the Posts and Telegraphs Workers' Union and the Communications' Union of Ireland.

A native of Moyvane, north Kerry, he joined Eircom's distant ancestor, the Department of Posts and Telegraphs, in 1970, as a trainee technician.

He was elected president of the union on five consecutive occasions.