The employee-owned group, seen as a retail bellwether, said on Sunday department store sales rose to 113.6 million pounds in the week to December 3.
While the figures were flattered by the snow which caused disruption to trade this time last year, sales were up 10.9 percent on the same week two years ago, indicating a robust underlying trading performance, John Lewis said.
The 9.6 percent figure was a gross number, inclusive of VAT sales tax and new space contribution.
Analysts estimate the figure at about 2.6 percent, excluding VAT and new space.
($1 = 0.6399 pound)
(Reporting by James Davey; Editing by Dan Lalor)