The growing advertising ambitions of technology powerhouses like Google and Microsoft are creating alarm in the executive suites of ad agencies.

Nokia said on Monday it would buy social networking start-up Plazes -- a smaller rival to services like Twitter and Jaiku -- as part of the world's top cellphone maker's push into Internet services.

Shares of Yahoo fell about 3 percent on Friday as reports of a brain drain raised fresh worries about the future of the Web company after it chose to partner with Google instead of Microsoft.

Microsoft sought on Friday to enlist support for its opposition to a new advertising collaboration deal between Google and  Yahoo, two sources familiar with the matter told Reuters.

Yahoo and Google face intense U.S. Justice Department scrutiny of their deal to share some advertising revenue, and the heat will likely increase under a new administration.

Mainstream advertisers normally gravitate toward wholesome characters from mainstream shows that steer clear of hot buttons. But in recent months, big brands like Coca-Cola, Subway and White Castle have been borrowing for their marketing efforts characters from “Family Guy,” which has been criticized for everything from anti-Semitism and sexism to homophobia and overall disgustingness, the New York Times reports.

Microsoft said on Wednesday it had purchased privately held digital television advertising technology company Navic Networks.

Yahoo investors are showing more interest in an alternate board slate proposed by billionaire Carl Icahn that was first formed to deliver the company to Microsoft in a now-defunct buyout.

Microsoft sought on Friday to enlist support for its opposition to a new advertising collaboration deal between Google and  Yahoo, two sources familiar with the matter told Reuters.

Microsoft is still open to negotiating with Yahoo after offering $1 billion in cash to buy its search business in a deal that would have delivered $1 billion in additional annual operating income to Yahoo.

Google announced a non-exclusive advertising services agreement with Yahoo, only hours after a decision by Microsoft to walk away from talks to acquire Yahoo.

Spending on online advertising leapt 40 percent in Europe last year to 11 billion euros ($17 billion), the Interactive Advertising Bureau (IAB) Europe said on Monday, as the Internet attracts ad budgets away from print.

U.S. antitrust regulators have given billionaire investor Carl Icahn the go-ahead to purchase large blocks of Yahoo stock, the Federal Trade Commission said on Friday.

Comcast 's digital unit is on target to turn profitable this year as revenues from search and advertising partnerships with Google and Yahoo exceed expectations, senior executives said.

Yahoo Chief Executive Jerry Yang said on Wednesday that a potential deal with Microsoft has tremendous power, but that the software giant appears no longer interested in a full merger.