New stores and demand for online and convenience shopping helped grocer J Sainsbury to meet forecasts with a rise in first-half profit in a tough trading environment that the group said was set to continue.

Britain's third-biggest supermarket group behind Wal-Mart's Asda and industry leader Tesco said on Wednesday profit before tax and one-off items rose 6.6 percent to 354 million pounds in the 28 weeks to October 1.

That was just above the average forecast of 352 million pounds in a Reuters poll of 17 analysts.

We expect the economic environment to remain challenging for the foreseeable future but we are confident of further good progress in the Christmas period ahead, Sainsbury's said.

(Reporting by Mark Potter; Editing by Helen Massy-Beresford)