Martin Talbot said: "What the future holds for 25 will unfold over the coming weeks and months, of course - but we can all be absolutely sure that more records will be toppled as Adele fever grips the nation in the run-up to Christmas."
Adele's third album has also "has done the seemingly impossible", according to Billboard magazine, and sold more than three million in one week in the US.
That is the highest one-week US sales since data tracking began in 1991, overtaking the previous record of 2.4 million set by N'Sync's No Strings Attached in 2000.
The singer has also just announced her first tour since 2011, playing in arenas across Europe from next February.