The "graph search" feature launched in a test version allows Facebook members to delve into the vast amount of information on Facebook, which is not available on Web search engines such as Google.
Facebook worked closely with Bing on the search feature that lets people get answers to queries such as "What songs do my friends like?" along with pulling in online information from the Microsoft search engine.
"We expanded our relationship with Bing," Facebook engineer Tom Stocky said during a press event at the social network's headquarters in Menlo Park, California, the first major announcement since Facebook went public in May.
"We worked closely with Bing to make Web search feel more a part of Facebook."
A fledgling version of graph search designed to let Facebook members do natural language searches to find places, pictures, movies and more that their friends liked began rolling out in for US English language users on Tuesday.
"We look at Facebook as a big social database," chief executive Mark Zuckerberg said. "Just like any database, you should be able to query it."
Facebook emphasized that the new effort was aimed at helping members find certain information archived within the network and in the content of friends, but had woven in the Web search power of Bing.
"I don't necessarily think a lot of people will be coming to Facebook to do Web search because of this, but it is a very good search engine," Zuckerberg said.
He said Facebook had discussed the project with Google but that "Microsoft was just more willing to do things that were specific to Facebook."
Zuckerberg said that "We are not indexing the Web here; we are indexing our map of the graph."
The new function goes back to Facebook's original goals of helping people make connections, according to its statement:
"When Facebook first launched, the main way most people used the site was to browse around, learn about people and make new connections," it said.
"Graph Search takes us back to our roots and allows people to use the graph to make new connections."
The social network offered examples of graph search queries including "friends who live in my city," "people from my hometown who like hiking," "friends of friends who have been to Yosemite National Park," "software engineers who live in San Francisco and like skiing," "people who like things I like," or "people who like tennis and live nearby."
Tech analyst Jeff Kagan said the new Facebook effort is a potential challenge to Google.
"If I were Google, I would see this as a Facebook warning shot across their bow. This is not an immediate attack, but nevertheless an attack is coming," Kagan said.
"Can Facebook transform the search engine world? If the answer is yes, then this is a bigger threat to Google."
Facebook also showed off how graph search could be used to find potential job candidates, such as engineer friends of NASA employees, or restaurant recommendations in potential challenges to LinkedIn, Yelp and other networks.
Zuckerberg and Facebook engineers stressed tools built in to protect privacy, a concern that typically fuels controversy every time the social network makes changes to the service.
"Privacy is going to be one of the big questions people have, which is why we want to get those tools not only built but out in front of people," Zuckerberg said.
"There is nothing visible now that wasn't visible before (at the social network)."
Zuckerberg said that building images from smartphone photo-sharing service Instagram into graph search, along with restaurant reviews, travel recommendations and more, would be part of Facebook's "road map" for years to come.
This could allow members to use Facebook to search for restaurants, travel and other recommendations instead of using Google or rating services.
Barclays analyst Anthony DiClemente said the new product "is an interesting concept, which may have the potential to foster additional user engagement."
But he added that "we do not believe that Graph Search poses a threat to Google search revenue" because Google "has a significant competitive advantage in its ability to deliver highly relevant information to its users."
Forrester Research analyst Nate Elliott said Facebook's initiative aims to get people more engaged on the social network.
"Facebook's worst nightmare is a static social graph; if users aren't adding very many new friends or connections... their personal network becomes less and less active over time," Elliott said.
"But that may be happening: We haven't seen significant growth in the average number of friends per user recently. Graph search seems designed to encourage users to add more friends more quickly. If it means users' personal networks change more frequently, and become more active, then that keeps them coming back to the site -- which is vital to Facebook's success."
Facebook shares slipped 2.7 percent to $30.10 on the news, while Google added 0.23 percent to $724.93. Microsoft gained 1.2 percent to $27.21.
