In a proxy filing today, aQuantive announced an Aug. 9 shareholder meeting to vote on the company's proposed $6 billion acquisition by Microsoft.

A letter to shareholders contained in the filing describes, in part, the mechanics of the transaction, which involves a Microsoft acquisition company called Arrow Acquisition. "The merger agreement provides for the merger of Arrow Acquisition with and into aQuantive, as a result of which aQuantive would become 100% owned by Microsoft."

The letter also reminds shareholders of the merger price: $66.50 a share, "a premium of approximately 85% over the $35.87 closing price of aQuantive common stock on May 17, 2007, the last trading day before the merger agreement was publicly announced." The company's shares gained slightly to close at $64.90 in an abbreviated holiday session.

aQuantive, a Seattle-based online advertising powerhouse, is holding the meeting in the swanky Hotel 1000, where shareholders will need to bring a couple of those aQuantive shares to trade for valet parking. Not surprisingly, the company's board of directors unanimously suggest a vote in favor of the transaction.

Meanwhile, according to this Bloomberg report, German authorities have started their review of the proposed acquisition, "triggering at least a 30-day review."

Microsoft submitted the bid, worth about $6 billion, on June 21, according to the German Competition Authority's Web site. The agency has opened an initial 30-day probe and will rule by July 23, Christiane Moch, a spokeswoman for the office said by telephone today.

The regulator can clear the takeover or start an in-depth probe that would last until Oct. 22, Moch said.