The AHCPS voted to accept the agreement by an 82% majority
The Association of Higher Civil and Public Servants (AHCPS) has become the first union to give its support to an extension of the Lansdowne Road Agreement on public sector pay.
Members of the AHCPS voted to accept the Public Service Stability Agreement by a majority of 82%.
The union represents more than 3,000 senior civil servants.
AHCPS says its members voted for the deal without a recommendation from the executive to accept or reject it.
General-secretary of the AHCPS, Ciaran Rohan said: "While we were somewhat disappointed that our members will be waiting a further five years to see their pay levels restored to pre-recession levels, we do welcome the progress made during the recent pay talks and we will continue in the months and years ahead to work with our members to deliver the full restoration of their pay.
"If we want to attract and retain experienced and skilled managers into the civil and public sector, we need to ensure that they are remunerated appropriately and in line with what's available in the private sector.
In this regard the association looks forward to engaging with the Public Service Pay Commission to address the problem of the level of remuneration at senior levels in the Civil and Public Service."
Mr Rohan is a member of the executive council of the Irish Congress of Trade Unions (ICTU), and participated in the pay talks.
The benefits in the deal, which runs from 2018 to 2020, range between 7.4% to 6.2% over three years.
Proposals also include restoration of pay cuts and ensure that over 70% of public servants will be making a further permanent contribution to their pensions.
The executive committee of the Teachers’ Union of Ireland (TUI) has previously recommended rejection of the deal.