70,000 Eircom shareholders who have not accepted the successful Valentia offer for their stock have been warned that money will be deducted from the value of their holdings if they do not sell before April 23.
The value of the shares still outstanding is believed to be 60 million euro or about 3.5% of the company, held by small shareholders.
Under company law, Valentia is entitled to force the remaining shareholders to sell at 1.335 euro after they received commitments representing 80% of Eircom stock.
A Mayo family challenged this in the High Court - but a reserved judgement said Valentia were acting in accordance with Irish law.
A letter from Computershare Investor Services to these 70,000 shareholders says that after April 23 those who have not sold will be liable for the full 'significant' administrative costs of keeping the money in trust for them.
An Eircom source said however that the costs could be about 10 euro a year for each shareholder after interest of just under 3.3% is added.