Twitter confirmed that it is working on new features designed to help companies use the microblogging site to grow their business.

A Twitter spokeswoman confirmed a limited beta test of new business-oriented features is currently underway. Spokeswoman Carolyn Penner said that a couple hundred companies are testing the feature in a closed beta process.

Twitter would not disclose details about the new features.

Last December, though, a company blog post disclosed plans for a feature called Contributors that would allow companies to better communicate with potential customers by allowing multiple bylined tweets.

Jason Goldman, the company's vice president of products, said in an interview that last week Twitter had started working with companies to create desirable business services.

"[Businesses] are looking for ways to understand the effectiveness of what they're doing on Twitter," said Goldman. "So much of the activity happens outside of Twitter.com, so they need to know what happens through a longer lens at the whole ecosystem. How many people were engaged in the tweet I wrote on desktop clients compared to the tweet I did on a mobile phone?"

Companies like Dell, Zappos.com and JetBlue are now using Twitter to provide information on new products and to offer discounts to new and old users.

Twitter said that as companies increasingly use the microblogging site, they are looking for ways to make it more effective -- to find out who is reading their tweets, and who is responding to them.

Though Twitter has acknowledged working on business oriented updates to the site, it remains unclear how the company will charge for such services.