Blair told the Financial Times in London it is the first of "a small handful" of similar positions he expects to take in the private sector.
Blair, who stepped down as prime minister last year, will use his experience and contacts to provide political and strategic advice to the firm, which has assets of $1.5 trillion, and take part in some client events, the report Thursday said.
"There are only a handful of people in the world who have the knowledge and relationships that he has," Jamie Dimon, JPMorgan chief executive, said.
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