Total net claims were £12.9bn, including £4.6bn of catastrophe claims in a year that saw Queensland in Australia devastated by Cyclone Yasi, Christchurch by further earthquakes and Japan by an earthquake and subsequent tsunami.
1,600 tornadoes battered US states in the South and Midwest and Hurricane Irene wreaked havoc on businesses and communities. As the year ended, floods in Thailand caused further devastation, with the third largest individual claim the market has faced after Hurricane Katrina and September 11.
Chief executive Richard Ward said in a statement: “Make no mistake, 2011 was a difficult year for the insurance industry ... Given the scale of the claims, a loss is unsurprising."
However he said it was reassuring that, despite the loss, the market's "financial strength has been maintained”.
The £516m loss in 2011 compared with a £2.2bn profit the previous yearThe loss, reflecting the aggregate financial performance of the 80 competing insurance syndicates that make up the Lloyd's market, is second only to the £3.11bn deficit it reported for 2001 following the September 11 attacks.
Last year was the second costliest on record for the insurance industry after 2005, with global catastrophe claims totalling nearly £70bn, according to Aon Benfield.
In August, Lloyd's reported a first-half loss of £697m following what it described as its "costliest six months on record".