US computer software giant Microsoft has announced it is to buy back another $40 billion of its shares.
Microsoft, whose share price has shed nearly 30% this year, said that the buyback would last until September 2013 and that it had completed its previous $40 billion stock repurchase program.
Standard and Poor's Ratings Services and Moody's Investors Service said meanwhile that they had assigned the highest AAA corporate credit rating to Microsoft and that the outlook was stable for the software giant.
Microsoft's revenues exceeded $60 billion in fiscal 2008.
