According to the latest figures from Kantar Worldpanel ComTech, Apple now accounts for 69 per cent of the Japanese market, 43 per cent in the United States, 35 per cent in Australia and 30 per cent in Britain.
The strong sales of its new models are linked to high levels of customer satisfaction, despite worries that the lower-end 5c could damage Apple's high-tech appeal.
Resurgent performances from competitors LG, Sony and Nokia have made making year-on-year share gains increasingly challenging for Apple. Android still dominates Europe, with at least 69 per cent of the market share. Windows Phone is now the third largest mobile operating system across Europe with 10 per cent (more than double its share in 2013).
Europe remains a high point for Nokia and Windows, but progress for both in the U.S and China – the world's two largest markets – is still slow.
China is likely to be the easier and more rewarding target for Windows, according to Dominic Sunnebo, strategic insight director at Kantar Worldpanel ComTech, because Nokia has a huge existing presence in the market, retains strong customer preference and can sell handsets at the right price to capture large numbers of users.
"You don't have to conquer China and the US to win in the smartphone market, but you do need success in one of them," said Sunnebo. "At the moment there are few signs of progress in either country for Windows Phone and momentum needs to be made soon before OS loyalty severely limits the available market."
Last week, Wells Fargo cut its rating on Apple from "outperform" to "market perform", sending shares down as much as 1.4 per cent in early US trading on Thursday.
The bank said there was "limited" opportunity for Apple to improve profits due to squeezed consumer conditions around the world, while the iPhone 6, expected to be introduced later this year, would be less profitable than previous models.