LONDON (Reuters) -Shell reported a 19% quarter-on-quarter drop in profit to $6.3 billion on Thursday reflecting weaker refining margins and oil and gas trading, though still beat analysts' forecasts.

The British company also said it would buy back a further $3.5 billion in shares over the next three months, at a similar rate to the previous quarter.

It kept its dividend unchanged at 34 cents per share.

Shell's second-quarter adjust earnings, its definition of net profit, exceeded analysts' expectations of $6 billion.

They rose from $5.1 billion a year earlier but were lower than the $7.7 billion profit Shell booked in the first quarter.

The quarter-on-quarter fall reflected lower prices and sale volumes as well as weaker trading at Shell's flagship liquefied natural gas division, which were a result of seasonally lower demand.

Lower refining margins and weaker oil trading also weighed on the results.