Google is putting its planned advertising deal with Yahoo on hold to allow more time for regulators to study the competition aspects.

"When we announced our advertising agreement with Yahoo in June we agreed to delay its implementation until October to give regulators time to look at the details," the company said.

"As we are still in conversation with the Department of Justice we have agreed to a brief delay in implementing the agreement while those discussions continue."

The deal, which would see Google supplying some of the adverts that appear with Yahoo's search results, has come in for heavy criticism from industry players like Microsoft.

Google had originally said that it would allow 100 days for regulators to investigate the deal and would go ahead later this month. However, the company has now said that it will delay for an unspecified period, thought to be about a month.

"The companies have agreed to a brief delay in implementing this agreement to continue our ongoing discussions with the Department of Justice," Yahoo said in a statement.

"We have had discussions with regulators and look forward to responding to their questions about this agreement."