Antitrust lawyers from the U.S. Department of Justice are still examining the proposal, but the delay is expected to be brief, The Washington Post reported Saturday.

"The companies have agreed to a brief delay in implementing this agreement to continue our ongoing discussions with the Department of Justice," Google said in a statement. Yahoo officials said, "We have had discussions with regulators and look forward to responding to their questions about this agreement."

The delay will be less than a month, unnamed sources told the Post.

Since the deal was announced in June, critics have weighed in by saying it will amount to a search engine advertising monopoly for the companies, who rank number one and number two in the booming field.