The European Union approved Microsoft's $26 billion acquisition of LinkedIn Corp. yesterday, after the software giant agreed to safeguards to assuage antitrust concerns.

The European Commission, the bloc's executive arm, said it was clearing the deal on the condition that, post-merger, Microsoft allowed other professional networking sites access to its Office programs for the next five years. The EU also stated that it must also grant computer manufacturers the option not to install the LinkedIn shortcut on desktop devices.

"A growing number of Europeans subscribe to professional social networks. Today's decision ensures that Europeans will continue to enjoy a freedom of choice between professional social networks," EU antitrust chief, Margrethe Vestager, said.

Microsoft announced its deal with LinkedIn in June. In November, Microsoft offered its Outlook programs to the EU to win approval for the deal.

The EU's approval deals a blow to Salesforce Inc., which lost out to Microsoft in the bidding for LinkedIn. It argued that Microsoft would gain an unfair advantage over competitors through its access to LinkedIn's vast pool of data.

However, the EU said it was unlikely the deal would allow Microsoft to shut competitors such as Salesforce, Oracle and SAP out of the customer relationship management market. It ruled that access to the full LinkedIn database was inessential to compete in the market.

To win EU approval, Microsoft also agreed to allow rival social networks to access Office's application programming interfaces, which allow discrete programs to communicate with each another.

Among other things, the measures proposed by Microsoft will allow for the display of profiles from sites other than LinkedIn in a calendar entry of a meeting.

In addition, the EU said Microsoft must allow rival networks access to Microsoft Graph, a program used to build applications that can tap data in the Microsoftcloud.