Sun Microsystems (SUNW) - Get Report was down 8.6% in preopen Island trading. After the close Thursday, the server maker slashed its third-quarter earnings guidance to 7 cents to 9 cents a share from the expected 15 cents and said revenue would grow just 10% to 13%, well short of the 30% analysts were looking for.

Sun also announced a $1.5 billion stock buyback. Sun hit a series of 52-week lows in anticipation of the revisions.