Nov 9 (Reuters) - Twitter Inc (TWTR.N) is rolling out its subscription product to the United States and New Zealand and will include several new features, the social networking site announced on Tuesday, as it pushes to diversify its revenue sources. Twitter Blue, which will cost $2.99 per month, will now include the ability to read some news articles without ads, upload longer videos and customize the navigation bar in the Twitter app. The San Francisco-based company, which earns most of its money by selling advertising, is eyeing more consistent sources of revenue by selling access to certain features to heavy Twitter users who flock to the site for news and current events. Twitter Blue subscribers can read articles from publications like the Washington Post, USA Today and Reuters without ads. A portion of the user"s Twitter Blue subscription will go to the news organizations, Twitter said.Subscribers can also pin important conversations to the top of the messaging inbox and change the color theme of their Twitter app. Twitter began rolling out the subscription service in June, launching it first in Canada and Australia. The company declined to say how many subscribers it has.