Investigating Microsoft antitrust allegations over the last ten years has cost the US Department of Justice $13.3m, according to its own estimates, including $7m on the Washington trial currently nearing its conclusion. The current investigation began in June 1995, but the $13m represents the money spent since October 1989, which includes the time during which the 1994 consent decree was drafted.

Under the consent decree, Microsoft agreed to change the way it licenses its software to personal computer manufacturers. There was also the investigation into Microsoft’s proposed acquisition of financial software house Intuit Corp in 1995, eventually blocked by the DOJ and abandoned. All agree the amount is small when compared with the 13-year IBM Corp investigation ($17m in 1982, not including expert witnesses) and AT&T Corp ($20m).

Microsoft isn’t saying what it has spent, but its public relations bill is certain to be somewhat larger than the $194,000 to Government spent on PR, which includes $147,000 posting documents onto the department’s web site.