Image caption There were big claims from the earthquake and tsunami in Japan in March

The insurance market Lloyd's of London has announced a loss for 2011, saying it was its worst year for catastrophe claims.

It lost £516m in 2011, compared with a pre-tax profit of £2.2bn in 2010.

It incurred net claims of £12.9bn in the year, including £4.6bn of catastrophe claims.

Catastrophes during the year included flooding in Australia and Thailand, the earthquake and tsunami in Japan and the earthquake in New Zealand.

"Make no mistake, 2011 was a difficult year for the insurance industry," said Lloyd's chief executive Richard Ward.

"I am disappointed that, given the exceptional level of catastrophes in 2011, insurance rates have not responded more positively."

Lloyd's of London is a market, in which syndicates meet brokers and agree to take on particular risks.

Its chairman said that the market was still in a strong financial position, but warned that 2012 would be another challenging year.

"Our strong capital position is unchanged and we were able to make a profit in the second half of the year despite the floods in Thailand and continuing low investment returns," John Nelson said.