Britain's fourth-biggest supermarket group said its like-for-like sales, excluding fuel, rose 8.1% in the 22 weeks to Jan. 3 - a period spanning its third quarter to Nov. 1 and the nine week Christmas trading period.

That compared with analysts' average forecast for a rise of 8.3% and a second quarter increase of 12.3%.

Industry data from market researcher Kantar, also published on Tuesday, showed all of Britain's supermarket groups benefited from unprecedented Christmas demand due to the pandemic, with UK shoppers spending 11.7 billion pounds ($15.9 billion) on groceries in December.

Restrictions to stem the spread of COVID-19 mean a large chunk of the population is still working from home and the hospitality sector is closed.

Supermarkets also had more mouths to feed, with many of the five million or so Britons who normally travel abroad for Christmas staying in the UK.

Kantar said Morrisons outperformed its bigger rivals - market leader Tesco, Sainsbury's and Asda.

"All customer and brand metrics are up, market share is up and we're growing as a multi-channel business," CEO David Potts told reporters.

He highlighted champagne sales up 64% compared with last year and whole salmon sales up 40%.

Potts also said Morrisons had not seen any material disruption to supplies from the European Union after Jan. 1 when a new trade deal kicked in.

Morrisons said it still expected 2020/21 profit before tax and exceptionals of 420-440 million pounds ($572-$599 million), prior to a business rates payment of 230 million pounds.

That is despite direct COVID-19 costs for the year rising to 280 million pounds.

Shares in Morrisons were down 0.2% at 0938 GMT.

On Monday, German-owned discounter Aldi reported a 10.6% year-on-year rise in UK sales for the four weeks to Dec. 24.

($1 = 0.7374 pounds)

(Reporting by James Davey; Editing by Kirsten Donovan and Mark Potter)

By James Davey