Microsoft on Thursday shrugged off concerns about a slowdown in the tech industry with solid quarterly earnings and an optimistic outlook for the first half of this year, sparking a strong relief rally in its shares.

The confident projection came on the back of strong PC demand, particularly in emerging market countries, along with a series of recent or new products ranging from server software to the Xbox 360 games console that together are expected to buttress the software company against the effects of a slowing US economy. Microsoft’s shares, which had already risen 4 per cent during the day, jumped another 6 per cent in after-hours trading, adding $30bn to its stock market value.