Google (GOOG) may be very close to dodging an antitrust bullet. Unnamed sources have told Bloomberg that Google “is poised to offer voluntary concessions that will end a 20-month U.S. antitrust probe of its business practices without any enforcement action being taken,” which would represent a major victory for a company that earlier this year looked headed for an antitrust lawsuit much like the one filed against Microsoft (MSFT) back in 1998.

Bloomberg says Google will offer up a series of voluntary concessions to end the probe and “is preparing a letter promising not to copy content from rival websites without permission and to allow advertisers to compare data from ad campaigns with their performance on other Internet search engines.”

Such measures are unlikely to satisfy many of Google’s rivals who have complained that the company uses its power in the search domain to favor its own services over those offered by its competitors.