TweetDeck&39's logo.

Twitter has agreed to acquire TweetDeck, a Twitter desktop client preferred by many of the social-media service's most active users, for $40 million in cash and stock, according to a CNN report.

The deal has not been officially announced yet, but a purchase agreement was signed today, according to the report, which cited sources close to the deal.

Twitter declined to comment on the report. "For all those who might be curious, we continue to not comment on rumors," the company said on its official public relations Twitter account.

TweetDeck has reportedly been the subject of a recent bidding war. In April, The Wall Street Journal reported Twitter was in "advanced talks" to acquire TweetDeck for $50 million, significantly more than the final deal was worth.

In February, TechCrunch reported that TweetDeck had been sold to UberMedia, a company that owns a portfolio of Twitter clients and related applications. However, Twitter soon blocked UberMedia's applications, citing a variety of concerns including trademark violations and privacy issues before reinstating them several days later.

If the report rings true this time, it makes sense for Twitter to own the client of choice among its most dedicated users. Twitter has aggressively pursued an acquisition strategy in building up a suite of applications. It purchased Tweetie in 2010 and turned it into Twitter for iPhone. In 2008, it purchased the Summize search engine and turned it into Twitter Search.