Google may be in "late stage" negotiations to acquire Twitter for more than $250 million, according to a report, after the microblogging service unveiled a more tightly integrated search feature earlier this week.

According to the TechCrunch.com blog, two sources close to the negotiations confirmed the acquisition talks, which come just months after Twitter turned down a $500 million offer from Facebook.

A third source told the blog that the talks were preliminary and concerned working together on a "real-time search engine" rather than a buyout.

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A Google spokeswoman told FOX Business, "We don't comment on rumor or speculation."

Twitter did not immediately respond to requests for comment, but in a blog posting titled "Sometimes We Talk," Twitter co-founder Biz Stone wrote: "It should come as no surprise that Twitter engages in discussions with other companies regularly and on a variety of subjects."

A source told Kara Swisher of the Wall Street Journal's tech blog All Things Digital that there were "seriously, no negotiations, no deal, nada."

Another source told her: "“There was a discussion with [Google executive Marissa Mayer's] group about real-time search and about product stuff. It was a couple weeks ago. It was very preliminary ... and that was that.”

Swisher herself dismissed the notion of buyout talks as "pure speculation."

Despite Twitter's meteoric rise in use among celebrities, politicians, journalists and ordinary citizens, it still doesn't have a solid plan for making money. It recently secured an additional $35 million in venture-capital investments.

On Thursday, Twitter unveiled a new search engine, allowing a user to see search results directly on their Twitter home pages.

The engine now makes it possible for users to search for keywords and phrases used by people they follow on the site, and the ability to "save" search results.

Experts say the search engine poses a threat to Google's dominance in traditional Web search and is appealing due to the potential for a real-time search, where a user could get a sense of what is being said about a particular topic instantly.

Google's Web crawlers work very fast, but lag behind real time by at least several minutes.

However, the prospects of an acquisition may come as a surprise to some after Google CEO Eric Schmidt earlier this month told a crowd gathered at a technology conference in San Francisco that Twitter was a "poor man's e-mail system."

Biz Stone appeared on the Comedy Central show "The Colbert Report" on Thursday evening and did not mention the possiblity of a Google buyout.

He did say that "we’re going to become a strong, profitable, independent company. We’re going to continue to be based in San Francisco."

Google's main headquarters, the Googleplex, is located in Mountain View, Calif. — about 35 miles south of San Francisco.

Twitter co-founders Evan Williams and Stone have already established a business relationship with Google, selling the free publishing tool Blogger to the search king.

With just 29 employees, Twitter has seen its Web traffic grow 900 percent over the past year. Web users from around the world have flocked to the service, which lets you send out postings of a maximum 140 characters to the entire world.