Mr Ahern stood back to allow Cabinet minister Pat Carey a better chance of retaining a single seat for Fianna Fail in Dublin North West.
The decision came on the same night that for the first time since 1973, Fianna Fail in Dublin Central did not select Bertie for their election ticket.
Instead, the ex-leader's constituency rival, Cllr Mary Fitzpatrick, was chosen alongside Cyprian Brady.
Ms Fitzpatrick -- whose father Dermot was a TD -- accused Mr Ahern of "shafting" her during the 2007 election campaign.
The then Taoiseach backed Brady in a last-minute leaflet drop even though there was no arrangement to do so.
Despite pulling in less first preference votes than Ms Fitzpatrick, Mr Brady was elected by virtue of massive transfers from Ahern.
Speaking to the Herald in advance of last night's convention, she accepted that herself and the sitting TD will probably be against each other for a single Fianna Fail seat.
"Dublin Central will be more interested because the two giants of previous elections, Bertie Ahern and Tony Gregory, will not be on the ballot paper.
"Joe Costello is probably the only guaranteed seat. Looking at national polls with where Labour, Fine Gael and even Sinn Fein are, they'll be expecting to take one seat each," she said.
"Fianna Fail will be battling for at least one seat. Ideally we'd be looking to take two but the polls wouldn't indicate that that is likely."
At last night's convention, Bertie Ahern openly pledged his loyalty to Brady. "I think I would be a traitor if I didn't back him," he said.
Asked about the possibility of taking two seats, Mr Ahern said: "To be honest, I worry about whether we will get one."
Mr Ahern also paid tribute to his brother Noel, who is bringing the final curtain down on the family's political dynasty.
Their other brother, Maurice, a former Lord Mayor, lost his seat on Dublin City Council in the 2009 local elections.
Noel's decision means that Fianna Fail will run only Pat Carey in the three-seater constituency of Dublin North West.
Mr Ahern said the party headquarters would have allowed him to run but were advising against it.
"They have certainly been talking to me about electoral strategy and that you would have a better chance by having only one candidate."
In Cork East, former food minister Ned O'Keeffe also confirmed his retirement.
Mr O'Keeffe -- a critic of Brian Cowen -- said it was time "to call it a day and let the younger people take over at this opportune time". His son Kevin is to contest the election instead.