"Babel" sold 600,000 copies in its first week of release according to figures from Nielsen SoundScan, almost doubling the sales of Justin Bieber's "Believe," which, until now, was the year's biggest debut with 374,000 units sold in its first week in June.

The album also notched the second-largest digital sales week with 420,000 downloads of "Babel," with only Lady Gaga's "Born This Way" ahead, which sold 662,000 downloads in its first week in 2011, fueled by Amazon offering the album for a discount price of 99 cents.

Lead single "I Will Wait" from "Babel" peaked at No. 23 on the Billboard Hot 100 singles chart and No. 2 on the Billboard Rock Songs chart.

The album also had a huge helping hand from online music streaming service Spotify, where it was streamed 8 million times over the past week, making it the biggest week for any album in the US this year, according to figures from Spotify. The streaming service also noted that one in ten of US Spotify users listened to a track from "Babel."

Mumford & Sons, formed in London, England, by lead singer Marcus Mumford, Ben Lovett, Country Winston Marshall and Ted Dwane, shot to fame with their 2009 debut album "Sigh No More," led by singles such as "Little Lion Man" and "The Cave." The album peaked at No. 2 on the Billboard 200 album chart.

The band are part of a new wave of singers taking the U.S. music chart by storm. Soul singer Adele swept the Grammy awards earlier this year with accolades in six categories and her heartbreak album "21" has sold more than 9.8 million copies in the US since its release in February 2011.

British boy band One Direction also made Billboard chart history earlier this year when they became the first UK group to debut at No. 1 with their first album on the album chart with their record "Up All Night," spearheading a new wave of boy band mania and embarking on a sell-out tour.

British singer-songwriter Ed Sheeran gained the highest US debut by a UK male solo artist with his album "+" since 2006, when Radiohead's lead singer Thom Yorke released his solo album. "The A-Team" singer is currently in the U.S. headlining a nearly sold-out tour.

"Babel" was one of five new entries in the top ten of the Billboard 200 chart on Wednesday. Green Day's ninth studio album "¡Uno!" landed at No. 2 with sales of 138,000, No Doubt entered the chart at No. 3 with their first album in a decade, "Push and Shove," with sales of 114,000.

Rapper Lupe Fiasco came in at No. 5 with his fourth studio set "Food & Liquor II: The Great American Rap Album Pt. 1," while electronic dance DJ Deadmau5 entered the chart at No. 6 with his sixth studio record "Album Title Goes Here."

(Reporting By Piya Sinha-Roy;Editing by Sofina Mirza-Reid)

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