The company announced its intention to switch to the first section of the Tokyo Stock Exchange as it announced quarterly profits of more than double the figure for last year.

If successful, the move could open up Yahoo Japan's stock to more big investors, which often prefer to buy shares available on the TSE first section because of its more stringent listing requirements.

As well as operating one of Japan's most popular internet portals, Yahoo Japan is the country's biggest provider of ADSL broadband internet connections - although dominant telco NTT is working hard to catch up.

Both companies have close to 3 million as long as all NTT units are counted together.

But NTT is now hoping a tie-up with Disney will help it pull ahead in a nation where the obsession with Mickey Mouse and other cartoon characters approaches religious levels.

Making the switch

Yahoo Japan is 42% owned by internet services company Softbank Japan, whose shares slipped ahead of the results along with those of Yahoo Japan itself, with another 33.5% held by US Parent Yahoo Corp.

The company's decision to switch to the TSE first section comes as Standard & Poor's, the global credit rating agency which also runs international stock indices, said it would add Yahoo Japan to its broadest Japanese index once the market closes on Thursday.

Yahoo Japan's value by market capitalisation is up 170% over the past year to 1.86 trillion yen ($15.7bn; �9.8bn), qualifying it to join the S&P Japan 500, S&P said in a statement.

Yahoo Japan's healthy profits - 4.54bn yen ($38.4m; �24m), up 108% for the April-June period over last year's results - reflect wildfire growth in the popularity of its auction services.

The company also has a hammerlock on the habit of using the internet to make phone calls, especially popular in Japan due to expensive phone tariffs.

Its lead in this area could benefit from a recent government decision to allow NTT to boost its rates by 5%, although its competitors are challenging the decision in the courts.