LONDON, Jan 2 (Reuters) -

The British arm of Aldi reported an 8% rise in sales in the four weeks to Dec. 24 to top 1.5 billion pounds ($1.91 billion) for the first time, while its smaller rival Lidl GB posted an even better 12% increase in the same period.

Both chains said they recorded their busiest ever day of trading on Friday, Dec. 22, with more than 2.5 million customers coming through the doors of Aldi on the day. ($1 = 0.7858 pounds) (Reporting by Paul Sandle; Editing by Sachin Ravikumar)