Washington/San Francisco: Yahoo Inc and Google Inc have drastically scaled back the scope of their search advertising deal, a person close to the discussions said on Monday, in a last-ditch effort to win US antitrust approval.

The move comes after Google appeared to be on the verge of walking away from the partnership, which was announced in June to foil Microsoft Corp's take-over attempt of Yahoo.

The deal has since drawn scrutiny from US regulators amid a growing chorus of criticism from advertisers.

The two internet companies have submitted a reworked proposal to the US Department of Justice that shortens their partnership to just two years from 10 years, the source said.