Power and gas grid operator National Grid said it expects to turn in a strong performance for the full year after a sharp rise in profits at the half year stage.Pre-tax profits in the six months to September 30 rose to £971m from £944m over the same period the previous year, driven by strong performances in all businesses, it said.Revenues in transmission operations rose to £1.9bn from £1.83bn, largely driven by a recovery in the UK. Gas distribution operations revenues increased to £1.85bn from £1.77bn helped by customer growth in the US and rate changes in New York.Electricity distribution revenues were up to £2.2bn from £1.95bn, with the rise largely attributable to hot summer weather, according to National Grid. Chief executive Steve Holliday said the company had seen a 'strong performance in all our businesses and the continued growth of our asset base. 'This period's profit growth is additionally driven by timing impacts, as we had a significant under-recovery of revenues in the first half of last year.'