Google is rolling out a new version of AdWords that will allow advertisers to manage and bid for ads across computers, smartphones and other devices within the same campaign, in a bid to simplify mobile advertising.

The company said Wednesday in a blog post that its new "enhanced campaigns" will roll out to advertisers as an option over the next few weeks, but it plans to upgrade all campaigns in mid-2013.

"This is a first step to help you more simply and smartly manage your ad campaigns in today's multi-device world," Sridhar Ramaswamy, Google's senior vice president of engineering, wrote in the blog post.

The new campaign includes the ability to manage bids across devices, locations and time, and have smarter ads with extensions optimized for varying user contexts. Users can, for example, bid higher for showing an ad to people who are close to their stores.

Google gave the example of an advertiser promoting a women's clothing boutique in San Francisco and an online store. Users can in a single campaign create ads tailored to customers searching on their mobile devices for women's clothing stores in San Francisco while also creating ads to appeal to those who want to shop for women's clothes online. "In a single enhanced campaign, you can show different ads and extensions to your customers, depending on what device they're using or when they're searching for you," Google said.

In the current AdWords platform, advertisers have to create multiple campaigns -- one for every city and every possible device combination, wrote Larry Kim, founder and chief technology officer of search marketing company WordStream in a blog post.

"Because this is so overwhelming, only the most sophisticated agencies and advertisers with large budgets and dedicated in-house PPC [pay-per-click] managers took advantage of Google's various mobile advertising features," he added.

Advertisers will now only need to specify a single bid adjustment factor for location and device, Kim said. For geo-specific and time-of-day based bidding, for example, the advertiser will be able to specify a bid adjustment multiplier from -100 percent to +300 percent. Users can also bid down by -100 percent to turn off mobile search.

Continuing growth in Google's advertising business helped increase its fourth-quarter revenue by 36 percent from the previous year. The company, however, saw a 6 percent decline in the cost of paid clicks, the money it charges when someone clicks on an ad, which puts pressure on the company to boost advertising and clicks in new growth markets such as mobile.

Certain decisions by Google including its clubbing of tablets with desktops for the new program may not find favor with advertisers, analysts said.