Federal Trade Commission Chairman Jon Liebowitz this week singled out Google for not adopting “Do Not Track,” the privacy feature that allows consumers the ability to opt out of online tracking by Web sites and marketing entities.

In an interview Monday with Politico, Liebowitz called out Google for not supporting Do Not Track in its Chrome browser.

Noting that Do Not Track had gathered momentum, Liebowitz said, “Apple just announced they’re going to put it in their Safari browser. So that gives you Apple, Microsoft and Mozilla. Really the only holdout — the only company that hasn’t evolved as much as we would like on this — is Google.”

Do Not Track has been promoted by the FTC and by privacy advocates including the Electronic Frontier Foundation (EFF), as the best way to help consumers protect their privacy.

The technology requires sites and advertisers to recognize incoming requests from browsers as an opt-out demand by the user. The information is transmitted as part of the HTTP header.

As Liebowitz said, Microsoft and Mozilla have added Do Not Track header support to their Internet Explorer 9 (IE9) and Firefox 4 browsers. While Apple hasn’t confirmed that the next version of Safari will include Do Not Track, developers have reported finding the feature in early editions bundled with Mac OS X 10.7, aka “Lion,” the upgrade slated to ship this summer.

That leaves Google’s Chrome and Opera’s browser on the outside. But neither plans to implement Do Not Track anytime soon.

Chrome has its own ideas about privacy, and also won’t commit to Do Not Track.

“We continue to offer the Keep My Opt-Outs plug-in for Chrome … which already works to permanently opt users out of most ad profiling,” a Google spokesman said in an email reply to questions.

Google declined to comment on whether it is considering adding Do Not Track header support to Chrome, but seemingly left the door ajar. “We’re encouraged that the standards bodies are working on these different header approaches, and will continue to be involved closely,” the spokesman said.