Dublin Corporation and the firefighters' unions have formally signed up to the productivity deal that will secure a 9 per cent increase for Dublin Fire Brigade staff. The agreement provides for a 7 per cent increase under the Programme for Competitiveness and Work, plus a 2 per cent payment "on account" for future productivity. Under the terms, signed yesterday, trade union representatives commit themselves to recommending acceptance to the 900 firefighters in the forthcoming ballot.