Apple Computer Inc. has begun offering rebates...

Apple Computer Inc. has begun offering rebates of between $150 and $800 on four of its computer models. The promotion, which began Feb. 11, will last to March 31 and will apply to Apple’s Macintosh SE, Macintosh II, Macintosh IIX and Apple II GS computer models. Cupertino, Calif.-based Apple made no formal announcement of the rebates. Instead, analysts and traders noticed advertisements appearing in Tuesday’s newspapers and immediately cut their earnings estimates.