HELSINKI: Nokia is reportedly about to be rebranded as Microsoft Mobile, signalling still-closer ties between the Finnish mobile phone company and the US tech giant.

According to a post on the Nokia Power User blog, which summarises the contents of a letter to Nokia's business suppliers, the renaming will take place as part of Microsoft's acquisition of the company.

"Please note that upon the close of the transaction between Microsoft and Nokia, the name of Nokia Corporation/Nokia Oyj will change to Microsoft Mobile Oy," the letter states.

"Microsoft Mobile Oy is the legal entity name that should be used for VAT IDs and for the issuance of invoices," it continued.

In a separate statement, Microsoft has said that its €5.4bn all-cash acquisition of Nokia is set to complete this week. A "strategic alliance" between the two companies was originally announced in 2011.

Speaking to Marketing Week, Annette Zimmerman, a research analyst at Gartner, commented: "The Nokia brand still has a high value to people. That doesn't mean the Microsoft brand is not known - but what does it mean to people?"

Nokia has suffered steady declines in market share over recent years, a trend exacerbated by the global consumer switch from feature phones to smartphones.

Figures from Gartner released in February suggest that Nokia's overall market share dropped from 19.1% of the mobile phone market in 2012 to 13.9% in 2013.

Over the same period, the share taken by Samsung, the world's largest handset maker, grew from 22% to 24.6%.

Data sourced from Financial Times/Nokia Power User/Marketing Week/Gartner; additional content by Warc staff