Digital marketing company aQuantive has been bought by Microsoft for $6 billion, it has been announced.

The move signifies Microsoft's first foray in to the world of internet advertising, a sector that has recently been attracting the attentions of most of the major internet companies.

Microsoft's acquisition of aQuantive is the company's largest to date.

The chief executive of aQuantive, Brian McAndrews, will run Microsoft's newly devised Advertiser and Publisher Solutions Group. The new body will be responsible for all of Microsoft's ad operations.

At a recent meeting for financial analysis PC World reports that Microsoft chief executive Steve Ballmer said: "We are going to be an advertising company."

"We need to embrace that. We need to be world class at that."

Earlier this year Microsoft's rival Google acquired the internet advertising giant DoubleClick for $3.1 billion.

US regulators are still investigating the acquisition amidst possible privacy and antitrust violations.