By Gerry Shih SAN FRANCISCO (Reuters) – Twitter Inc unveiled a redesign of its user profile pages on Tuesday, the latest in a series of steps promised by the company to bring new users to the seven-year-old service. In response to an all-time low in user growth figures during the recent quarter, Twitter Chief Executive Dick Costolo told worried Wall Street analysts that the company would make a number of changes to freshen up the service. Users can now pin a tweet to stay at the top of their feed, a rare instance of Twitter departing from the continuously rolling format that has defined the service. The new layout, which will be available to a small group of users initially, will be widely deployed to Twitters 241 million users in the coming weeks, the company said.