LONDON (AFP) -Anglo-Dutch oil giant Royal Dutch Shell posted a 6.0-percent rise in first-quarter profits, helped by better performances at its refinery and chemical units, the group said on Thursday.

However group revenue fell, hit by lower output and weaker oil prices, the world’s second biggest energy group added in its earnings statement.

Shell said net profit climbed to 7.281 billion dollars (5.351 billion euros) during the first three months of 2007 compared with the first quarter of 2006.

Shell booked a one-time gain totalling 371 million dollars in the first quarter of this year, largely from asset disposals.

“These are again competitive results,” chief executive Jeroen van der Veer said in comments accompanying the results statement.

Profit at its Oil Products unit increased to 1.488 billion dollars.

“Earnings reflected higher refinery and marketing margins,” Shell said.

Meanwhile profit at its chemicals unit more than tripled to 480 million dollars.

Total group revenue fell 3.3 percent to 73.48 billion dollars.

Production fell 6.0 percent to 3.5 million barrels of oil equivalent per day, partly owing to disruptions at Shell’s operations in Nigeria.

“Efforts continue towards restoring safe operational conditions in the Niger Delta,” Shell said.

The Niger Delta, a swathe of creeks and swamps and the size of Scotland, is home to Nigeria’s multi-billion dollar oil and gas industry.

But the region has seen a resurgence in violent attacks on oil firms and personnel over the past two years.