FACTBOX - Global writedowns and credit losses

(Reuters) - A 5.9 billion pound writedown on risky assets sent Royal Bank of Scotland to a first-half loss of 691 million pounds -- better than feared, but still one of the biggest losses in corporate history.

RBS, which has written down more than 8 billion pounds, has been one of the banks hardest hit by the credit crunch, but it is not alone.

A year in, banks have lost around $410 billion (214 billion pounds) of assets tarnished by the U.S. subprime housing crisis, forcing them to raise billions from their own shareholders and outside investors.

Below is a summary of the credit-related writedowns and losses recorded by major institutions since the credit crunch hit in the third quarter of 2007.

FIRM: AMOUNT:

(billions of dollars)

Citigroup 57.50

Merrill Lynch 46.80

UBS 36.70