Tony Blair is to take a job with JPMorgan Chase, the international financial services and investment banking group, The Times learnt last night.

The former Prime Minister is to be a political adviser to the American firm which operates in more than 50 countries and whose assets are put at $1.5 trillion, with interests also in commercial banking and private equity.

Sources said last night that Mr Blair would advise the bank on global political issues. His salary is unknown but is likely to be more than £500,000.

Jamie Dimon, chief executive of JPMorgan Chase, said Mr Blair would be “enormously valuable” to the company. “There are only a handful of people in the world who have the knowledge and relationships that he has.”

Mr Blair said that he expected to agree to “a small handful” of similar appointments with other companies in different sectors. He is believed to have held talks with other banks, such as HSBC and Citigroup, about such roles and there was speculation at the end of last year that he would take a position at Credit Suisse because of his close friendship with Russell Chambers, one of the bank’s senior executives.

Mr Blair told the Financial Times: “I have always been interested in commerce and the impact of globalisation. Nowadays, the intersection between politics and the economy in different parts of the world, including the emerging markets, is very strong.”

The JPMorgan Chase job was brokered by Robert Barnett, the Washington lawyer who also negotiated a reported £5 million advance for Mr Blair’s memoirs.

Mr Dimon, who is one of the leading Democrats on Wall Street, said he approached Mr Blair personally. “I went to visit him and we hit it off.” He said it was important to both men “to try to make the world a better place and have a bit of fun doing it”.

Mr Blair will add the part-time advisory role to his job as a Middle East envoy and speaker on the international lecture tour, which is earning him about £100,000 a speech.

It will be the first big City appointment for Mr Blair, who is on course to earn £5 million from the publication of his Downing Street memoirs in 2009. Mr Blair has struck a deal with publishers on both sides of the Atlantic that has only been bettered by the sums paid to Bill Clinton, according to publishing sources.

A source close to Mr Blair said: “Tony is focused on and enjoying the challenge of his task in the Middle East. He continues to receive requests to speak and, as his schedule allows, he does so on both a paid and unpaid basis.”

Mr Blair’s new job will have been approved by the Advisory Committee on Business Appointments, which vets all jobs given to former ministers.

He is not being paid a salary in his role as Middle East envoy, working on behalf of the Quartet — the US, Russia, the UN and the EU. However, Britain has donated £400,000 to a UN development programme trust fund, which provides “operational and technical support” in the Jerusalem office of Mr Blair.

In a Commons written reply, David Miliband, the Foreign Secretary, said that Britain had seconded four staff to Mr Blair’s team, and that other international donors were supporting his work.

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