Minister for Transport Martin Cullen is to appoint four new worker directors to the board of the Dublin Airport Authority (DAA).

The four, who were elected a fortnight ago, hoped to attend the last board meeting of the DAA, but without official appointment notices, this was not possible.

Three of the four worker-directors are from Siptu, the largest union at the airport. Frustration had been growing in Siptu about the Government's failure to appoint them. In recent months, Siptu has been in talks with businessman Ulick McEvaddy about a new terminal at Dublin Airport.

However, Siptu pointed out that any shareholding in Mr McEvaddy's project will be held by airport workers, not Siptu itself.

Dermot O'Loughlin, head of Siptu's civil aviation branch, said last night the talks with Mr McEvaddy were "irrelevant" to the appointment of the directors.

The four appointees are Barry Nevin, president of the SIPTU civil aviation branch; Brian Lynch from the airport's cleaning department; Marion Keeting from human resources at the DAA, and Pat Fitzgerald, from the catering division based at Shannon.

The airports remain under the DAA's ownership, but once the Government approves their business plans, Shannon and Cork are free to become autonomous.

The balance of power on the DAA board could be important in the period ahead, with cost cutting expected at Shannon and possibly at Dublin. The issue of whether the DAA builds and operates a new terminal at Dublin is also likely to prove sensitive.