Pretax profit rose 21 percent to 1.67 billion pounds for the six months to end-June, compared with 1.38 billion the previous year, Lloyd's said in a trading statement.

Ninety-four syndicates underwrite insurance at Lloyd's, housed in one of the most recognisable buildings in London's main financial district, with listed companies including Catlin (>> Catlin Group Limited), Hiscox (>> Hiscox Ltd) and Amlin (>> Amlin plc).

Investment income rose to 642 million pounds, up from 247 million in the first half of 2013, helped by higher yields in the market's corporate bond portfolio, acting finance director John Parry told Reuters.

But Lloyd's combined ratio, a measure of profitability showing how much insurance premium is paid out in claims and expenses, deteriorated to 88.2 percent from 86.9 percent. A ratio below 100 percent indicates an underwriting profit. "It's been a fairly benign period for major catastrophes," Parry said.

Insurance underwriters tend to perform less well in the absence of major catastrophes, as insurance premiums fall.

New players such as hedge funds in the reinsurance sector, which helps insurers pay large damage claims in exchange for part of the premium, have also made the sector increasingly competitive.

But Lloyd's return on capital rose to 16.5 percent from 14 percent a year ago.

"Against the broader economic environment, insurance looks quite attractive, there's a lot of talk of it as a diversifying investment," Parry said.

(Reporting by Carolyn Cohn; Editing by David Holmes)

Stocks treated in this article : Catlin Group Limited, Amlin plc, Hiscox Ltd