King Digital Entertainment, the British developer behind the wildly-addictive mobile game Candy Crush, says that it could be valued at up to $US7.6 billion ($A8.49 billion) in its eagerly-awaited upcoming flotation.

The planned listing on the New York Stock Exchange, unveiled last month, is the latest in a series by internet and gaming firms over the past three years — the most high-profile being Facebook and Twitter.

King said on Wednesday that it was planning an initial public offering of 22.2 million shares each priced at between $21 and $24 a share, believing it could raise nearly $US613 million ($A685 million) in its initial public offering.

In a regulatory filing on Wednesday, King Digital Entertainment said it plans to sell 15.3 million shares in the offering.

Existing shareholders will sell an additional 6.7 million shares.

Candy Crush was the most downloaded free app on iPhones and iPads in 2013, beating Facebook, Google Maps and YouTube.

The shares are expected to be priced between $US21 and $US24, for a total of between $US466.2 million and $US532.8 million.

Underwriters have the option of buying up to an additional 3.3 million shares. That could raise an additional $US69.9 million to $US79.9 million.

Shares would be listed on the New York Stock Exchange under the symbol KING.

Candy Crush – King’s top-seller – started life as a Facebook game in 2012 but can also be played online and on smartphones.

Millions of commuters, teenagers — even pensioners — worldwide clock in daily to test their skills at the game, which basically involves moving brightly coloured sweets around a grid to get at least three of a kind in a row.

The highly-addictive game is free, but players can pay for extras to smooth their passage through its more than 500 levels.

Candy Crush records some 700 million sessions a day and racks up daily sales of $US850,000 ($A949,667.62), according to the IDATE digital research and consultancy firm.