* H1 pretax profit up 99 pct to 33.2 mln stg
* Underlying revenue up 2.7 percent to 2.07 bln stg (Adds details on website traffic, expansion, background)
LONDON, Aug 5 (Reuters) - Britain's largest car dealer Pendragon saw its profits rise 98.8 percent in the first half of the year with increased online visits helping push up used and new car sales.
The company said 8 million people visited its website in the first six months of 2014, a 16.2 percent rise on the same period of last year, also helping to bolster its aftersales services.
Pendragon, which runs more than 250 retail outlets and trades under the names Stratstone, Evans Halshaw and Quicks, saw profit before tax rise to 33.2 million pounds ($56 million) in the six months to 30 June 2014.
"The internet transformation of our business continues to yield sizeable benefits for the group," said Chief Executive Trevor Finn in a statement.
The group has focused on improving its online presence in recent months, with high-definition videos of selected vehicles allowing customers to peruse online before often visiting a dealership in person to make their purchase.
Underlying revenue at the dealership rose by 2.7 percent to 2.07 billion pounds and Pendragon said it expected its full-year performance to be "comfortably in line with expectations."
Tuesday's results are also a further sign of Britain's buyout car market, with new vehicle sales expected to hit 2.4 million in 2014, up more than 6 percent on last year and returning to levels seen before the 2008-09 financial crisis after, which they nose-dived.
Pendragon said it was continuing with its strategy to increase the number of outlets it has across Britain.
In February, Finn told Reuters he was eying expansion in cities including Bristol, Ipswich and Norwich, where the company would open dealerships if the right opportunity arose.
$1 = 0.5930 British Pounds Reporting by Costas Pitas; Editing by Louise Heavens and David Holmes