In a statement, the company said jobs would be cut across business units, markets and staff groups.
The move is expected to result in savings of $175 million.
Amex is also planning to cut back its investment in market and business development in a bid to save a further $500 million, while reductions in spending on consultants, travel and general overheads should save another $125 million.
The job cuts are on top of the 7,000 redundancies announced by the company in October 2008.
Last month, Amex reported that its net profits for the first quarter of 2009 had fallen by 56 per cent to $437 million.
It was recently adjudged to be among the healthier of the 19 financial institutions subjected to the US government's stress tests. Amex was one of nine companies the Federal Reserve said did not need to raise extra capital in order to weather a severe downturn.