Twitter has acquired Cloudhopper, a text messaging infrastructure startup that Twitter is using to connect directly to mobile carrier networks in countries around the globe. Terms of the deal were not disclosed.

In making the announcement Friday, Twitter said it has been working with Cloudhopper for the last eight months to expand Twitter's microblogging service. Twitter's short message service (SMS) enables users to broadcast and receive text messages with a 140-character limit on any device, including some of the cheapest mobile phones.

Twitter processes nearly a billion text messages per month and says that number is growing around the world "from Indonesia to Australia, the U.K., the U.S., and beyond." The company said it has bought Cloudhopper in order to further grow and scale Twitter's service.

Cloudhopper says on its Web site that it powers mobile messaging campaigns in North America, Europe and Africa. The company, headquartered in Seattle, Wash., was founded in late 2008 by Joe Lauer, who has agreed to join Twitter.

The latest acquisition is the second this month for Twitter. About two weeks, Twitter announced plans to buy Atebits, maker of the popular Tweetie client for posting and receiving messages from Twitter via an Apple iPhone.

While the Cloudhopper buy is uncontroversial, the Atebits acquisition raised concerns among third-party developers who feared Twitter would continue to add features to its service that would gut their businesses. Other developers have developed iPhone applications related to Twitter.

In March, the number of visitors to Twitter reached 9.3 million, an increase of more than 5 million visitors, or 131% from February, according to ComScore.