MOUNTAIN VIEW, California: Google has altered its policy that limited the use of brand trademarks in US search ads solely to their owners, a move it argues will increase the effectiveness of paid placements, but which could also increase the cost of buying keywords.

Previously, only brand owners could employ, or else authorise the use of, the names of their assets in ads placed via the search giant's AdWords system, but this will change from the middle of June.

Under the revised rules, companies such as retailers and comparison websites will be able to mention specific brands in their ads without receiving express permission from their owners.

Terri Chen, senior trademark counsel at Google, argued this change "will generate higher-quality ads and that more people will click on them."

She also added that the change in policy will "help consumers because it will allow them to see more ads from more resellers."

The Mountain View-based company will also ensure that certain terms and conditions are met before allowing advertisers to use the names of other companies' properties.

Paid-for ads will not be able to portray brands in a negative manner, and retailers must sell a significant quantity of particular product to qualify to use the system.

Sites selling fake goods will also be barred from the service, and pages linked to search ads must include a facility to purchase the brand in question.

However, Bryan Wiener, chief executive of digital agency 360i, argued that "if you're a brand selling products or services directly, your costs are going to go up" when buying search terms.

This is because there is going to be "increased competition" to buy brand-based keywords, as retailers are "going to be bidding on those keywords at a greater rate."

Comparison sites and aggregators will also "have a greater opportunity to build market share," which may come at a cost to brand owners.

Data sourced from AdAge; additional content by WARC staff