Australian giant Wesfarmers Ltd has announced that overall group profit increased 46 per cent during the first half of the year, boosted by results at the Coles supermarket chain.

Accelerated growth in the fresh food sector and good performances by Target, Kmart and Officeworks also contributed to the improved results, the Reuters reported.

'Particularly pleasing are the signs that the turnaround in Coles is gaining traction,' said managing director Richard Goyder. 'Despite the impact of a tougher consumer environment, the group's retail businesses have generally weathered the downturn well and the Coles turnaround is gaining momentum.'

Food and liquor sales jumped 3.8 per cent during the second quarter of the year, the group said, up from 1.3 per cent in the first quarter.

Despite the first-half results, the group warned that Coles would remain on guard against changes brought on by the economic climate: 'Customers will become increasingly cost conscious. Delivering the necessary change required to a business that had lost its way will take time,' Wesfarmers said in a statement.