Online gaming firm 888 has set the price range for the planned sale of its shares on the London market at between 162-212 pence per share.
Revenues are continuing to grow, 888 says
The range will give the company a market value of between £546.1m and £714.6m ($1bn-$1.3bn) when it floats its shares later this month.
The Gibraltar-based group runs several online sites, including Pacific Poker.
Confidence in the online gaming sector was hit last week when Partygaming warned future market growth could slow.
Shares in Partygaming, which operates the world's largest online poker site, fell more than 30% after the warning.
When 888 first announced its attention to float its shares, the listing was expected to give the firm a valuation of at least £700m.
At the weekend, 888 denied reports that it was being forced to cut its float price, or even scrap the flotation, as a result of the Partygaming warning.
As it announced its intended share price range, 888 said that net gaming revenue from its casino business was up 14.2% in the first half of 2005 compared with a year ago.
Net gaming revenue from its poker interests jumped by 226%, although the firm said it did not expect growth to continue at this rate.
"As one of the world's most popular online gaming companies we have a very strong story to tell in respect of our position and our future strategy for growth," said 888 chief executive John Anderson.
888 said it would announce its final float price "on or around" Thursday 29 September.