With Saturday set as a deadline for Yahoo to accept its acquisition bid of $43-billion, Microsoft CEO Steve Ballmer has indicated that his company has no intention of upping its offer and would be prepared to walk away from the deal if necessary.

Speaking at a technology conference in Milan, Ballmer says he feels the amount offered reflects Yahoo's true worth and that there are no plans to raise it.
"We know what Yahoo's worth. $44 billion is a lot of money," Ballmer says, adding that Microsoft is "prepared to move forward alone without Yahoo" if the bid doesn't succeed.
Meanwhile, Reuters reports that the US Justice Department is investigating Yahoo's test of the Google ad engine. The two companies recently announced a limited two-week experiment with an eye to a possible future partnership. The trial is limited to 3% of Yahoo's searches, but if this was expanded it could see Google's ad engine accompanying 80% of all search results.
The Justice Department is apparently also investigating a telephone call between Google CEO Eric Schmidt and Yahoo CEO Jerry Yang allegedly offering help in combatting Microsoft's acquisition offer.