The “porn mode” feature of the Chrome web browser Google released Tuesday could hamstring ad targeting, a key driver of the company’s profits, an analyst said.

The browser, released in public beta, includes privacy features, dubbed “porn mode” by online wags, that allow users to erase all evidence that they visited a web site.

The features, however, also could hinder efforts by Google and others to deliver “highly targeted ads,” UBS analyst Benjamin Schachter said in a research note.

Microsoft’s newly released beta version 8 of Internet Explorer, the No. 1 browser, also includes a privacy mode.

Shares of Google climbed $15.28, or 3.3 percent, to $478.57 in late morning trading on the Nasdaq.

The analyst said that the browser would let Google bypass Microsoft in collecting data and user behavior.

Mr. Schachter (no relation to the reporter) said that Google’s decision to roll out a browser was triggered by concerns about Microsoft’s “ability to control the user experience” and the possibility that the maker of the ubiquitous Windows operating system “may get more aggressive with the browser” as court rulings about monopolistic practices recede into the distance.

Still, how many computer users will adopt the Google’s Chrome remains an open question, he said.

Google “has launched many products [with] much hype that have gone nowhere,” Mr. Schachter noted.

Microsoft’s Internet Explorer is the No. 1 web browser with a 72.2 percent market share, followed by Mozilla’s Firefox at 19.7 percent and Apple’s Safari at 6.4 percent, according to Net Applications.

Mozilla, an open-source foundation, receives funding from Google, which has indicated it will continue its support despite the launch of a competing browser.

The UBS report said that Chrome also could advance Google’s ambitions in “cloud computing,” in which applications don’t reside on a user’s computer, but are tapped from distant servers via the Internet.

In 2001, the Department of Justice entered into an agreement with Microsoft to curb it anti-competitive practices.