Microsoft shares were down nearly two per cent on Wall Street on Wednesday, local time, amid an unconfirmed report that the US software giant had agreed to purchase Nokia's mobile business for $19 billion (NZ$23.2bn).
Microsoft shares were 1.92 per cent lower at $24.53 in early afternoon trading in a market that was down overall.
The website Boy Genius, or BGR.com, reported that according to industry insider Eldar Murtazin, Microsoft has struck a deal to purchase Nokia's mobile phone business for $19 billion, a claim dismissed by a Nokia spokesperson.
"Eldar's rumours are getting obviously less accurate with every passing moment," the Nokia spokesperson told the site.
Asked about the report, a Microsoft spokesman said "Microsoft does not comment on rumours or speculation."
Nokia shares fell 17.5 per cent on Tuesday after the world's top mobile phone maker sharply downgraded its second quarter outlook. They were down another 10 per cent at one point on Wednesday, falling to their lowest level since 1998.
While it remains the world leader, Nokia has in recent years seen its global market share dwindle amid tougher competition in the high-end smartphone sector.
In September, Nokia hired former Microsoft executive Stephen Elop to be chief executive of the Finnish company. In February, Nokia announced it was abandoning its smartphone platform to adopt Microsoft's mobile operating system.