Twitter’s booming Japanese operation generated 10% of global revenues for the first time in the second quarter of 2016.
Sales in Japan have at least doubled on a year earlier to $61.2m (£47m), according to an analysis of the company’s stock market filings.
By contrast, Twitter’s growth in the UK has slowed. The UK made 11% of worldwide turnover ($33.4m) in the second quarter of 2015, but it has fallen below 10% since then.
A source close to Twitter suggested the latest figures were a reflection of its strength in Japan, where it reportedly has more users than Facebook, rather than a slowdown in the UK.
Twitter only gives a breakdown of revenue on a country basis when sales are at least 10% of worldwide turnover.
That has meant the American parent company has no longer had to disclose UK revenue to US investors since last summer.
The UK first generated 10% of group sales for Twitter in 2013 when the company was preparing for its US stock market flotation.
The parent company declared that its UK operation made $66.5m from the UK in 2013 and more than doubled sales to $140.3m in 2014.
Twitter did not reveal its 2015 UK sales in its US accounts, published in February, because sales had fallen under 10% of group turnover – below $220m.
The UK has been the only country to generate more than 10% of worldwide sales outside the US until now.
Twitter has 35 million users and Facebook has about 25 million in Japan, according to a report in The Wall Street Journal earlier this year.
Twitter reported several years ago that it had 15 million users in the UK and that number is thought to have risen, although a spokesman declined to give an updated figure. Facebook is estimated to have around 37 million UK users.
Twitter’s stock market price has fallen from a peak of nearly $70 at the start of 2014 to $20 as Wall Street investors have become concerned about the company’s stalling user numbers and its struggle to match Facebook’s growth.
Twitter added just nine million users between June 2015 and June 2016 to take its global user base to 313 million.
There has been speculation about a sale or takeover bid. Google, News Corporation and private equity firms have been tipped as possible suitors.
Twitter’s sales from the UK are likely to slow further in dollar terms in the near-future because sterling has slumped in value by 10% against the US currency since the Brexit vote at the end of June.