Motor insurer Admiral said its 2011 profit rose by a better-than-expected 13 percent, with continued strong growth in customer numbers in the UK outweighing a wider loss at its fledgling international operations.

Admiral, which insures one in ten cars on Britain's roads, made a pretax profit of 299 million pounds last year, it said on Wednesday, up from 266 million pounds in 2010, and ahead of the 289 million pounds expected by analysts in a company poll.

Analysts had initially pencilled in a 22 percent profit rise, but slashed their forecasts in November when Admiral warned it had been hit by a jump in personal injury claims, an industry-wide trend it had previously avoided.

It has been a disappointing year, Admiral Chief Executive Henry Engelhardt said in a statement.

Not because it was a bad year, but because so much more was expected.

Admiral shares closed at 1,040 pence on Tuesday, valuing the company at about 2.8 billion pounds. The stock has lost more than a third of its value in the past year, lagging a 14 percent drop in the Stoxx 600 European insurance index.

Admiral, which also trades under the Bell, Diamond and Elephant brands and owns price comparison site, is paying a dividend for the year of 75.6 pence per share, an increase of 11 percent.

(Reporting by Myles Neligan, Editing by Rosalba O'Brien)