FILE PHOTO - Mike Coupe, CEO of Sainsbury's poses in a store in Redhill, Britain, March 27, 2018. REUTERS/Peter Nicholls

LONDON (Reuters) - The chief executive of Sainsbury's SBRY.L was filmed singing "We're in the Money" hours after announcing that the supermarket he runs would buy rival Asda, boosting his company's value by 860 million pounds ($1.18 billion).

CEO Mike Coupe was waiting in a studio when cameras caught him singing the song from the musical 42nd Street in footage that was later released by British broadcaster ITV.

“We’re in the money, the sky is sunny. Let’s lend it, spend it, send it rolling along,” he sings before sipping his coffee.

The Asda deal has already made Coupe significantly richer, with his 1.28 million shares going up in value by 500,000 pounds following the announcement.

Coupe apologized, saying he was sorry if anyone was offended.

“This was an unguarded moment trying to compose myself before a TV interview. It was an unfortunate choice of song, from the musical 42nd Street which I saw last year,” he said in a statement emailed by Sainsbury’s.

Sainsbury's said on Monday it would buy Asda, owned by Walmart WMT.N for around 7.3 billion pounds, in a bold attempt to overtake long-time leader Tesco TSCO.L as Britain's biggest supermarket group by market share.

($1 = 0.7273 pounds)