In the statement he said he felt it his duty to stay with the SDLP in the task of working for "a new and agreed Ireland based on a lasting settlement and a lasting peace."
Describing the decision as very difficult, Mr Hume said he had been given many good reasons for seeking the presidency but that these had been outweighed by "the very serious crisis in the north."
His decision means he will lead his party into the political talks which re-open in Belfast today. It also means that Northern Ireland will not lose a man who for almost three decades has been a commanding figure in its political landscape.
Yesterday's announcement brought to an end a period of uncharacteristic prevarication on the part of the SDLP leader, who early last month said he would take some time to make up his mind on the matter.
The current president, Mary Robinson, leaves the post shortly to take up a senior position with the United Nations. She said yesterday, during a visit to Belfast, that long-term sustainable peace was within reach "if the risks for peace that people have taken in their own lives can be reflected in the more difficult set of circumstances of a political framework."
Opinion polls and other evidence in the Republic have shown that Mr Hume's popularity far outstripped that of any of the other potential contenders to succeed Mrs Robinson. The almost universal feeling is that if he wanted the post he could have had it.
Mr Hume has been a pivotal figure at the centre of political negotiations since the late 1960s, in more recent years playing a crucial role in the peace process which has led to two cessations of IRA violence. During that period he has also amassed a formidable stockpile of political capital in Dublin, Washington and Europe.
As such, his departure at a time when efforts are being made to underpin ceasefires with new political arrangements would have been a major and potentially traumatic moment for Irish nationalism. The decision to stay means the SDLP leader, who was there at the eruption of the troubles, will face a chance of realising his ambition of being present at their conclusion.
Mr Hume's decision creates a crisis for the main Dublin Government party Fianna Fail (FF). Former Taoiseach Albert Reynolds now becomes the front- runner in seeking its nomination, but party leaders are worried that his tendency to speak out on delicate Northern Ireland issues could wrongfoot his successor Bertie Ahern during the imminent multi-party talks.
Despite his achievements in advancing the 1994 IRA and Loyalist ceasefires, Mr Reynolds' image at home has suffered from events surrounding the collapse of his government, his role in allowing controversial credits for beef exports to Saddam Hussein's Iraq which may have cost taxpayers pounds 100m, and his involvement in a series of legal actions against the press.
Mr Reynolds' insistence on running, regardless of Mr Hume's possible aspirations to become head of state, may have helped discourage the SDLP leader by threatening an unseemly nomination dogfight before he even got on the ballot paper.
Mr Hume may also have been put off by arguments in Dublin, notably from Labour politicians, that voters would feel short-changed if Mr Hume was given a free run by all main Dail parties, removing the need for an election. Though pressed to run by deputy premier and Progressive Democrat leader Mary Harney, Mr Hume was not invited to stand by FF.
Fine Gael have two declared hopefuls, Mary Banotti MEP, 58, a grand-niece of Michael Collins, and former junior minister Avril Doyle, 48.
Labour will consider their options for supporting either an internal candidate or a non-party figure at a meeting today. FF and Fine Gael will discuss their selection at parliamentary party meetings next week. Independents and Greens are supporting Joycean scholar and gay rights activist David Norris.
Singer Dana, backed by a small right-wing Christian prayer group, is unlikely to secure the 20 parliamentary or four local council endorsements required for a nomination.Reuse content