US magazine publisher Time Inc. said Wednesday it will produce versions of all of its 21 US titles for tablet computers by the end of the year.Time Inc., a division of US media and entertainment giant Time Warner, is already producing tablet editions of Time, its flagship news magazine, Sports Illustrated, People and Fortune. Other Time Inc. titles include InStyle, Real Simple and Entertainment Weekly.\"In the coming year, there will clearly be many more consumers using tablets, accelerating demand for content and driving advertiser interest,\" Time Inc. executive vice president Maurice Edelson said in a statement.\"Having our entire portfolio available on tablets will create a significant new digital reach for our advertisers,\" Edelson said.Time Inc. said the company\'s digital magazine and other content applications have been downloaded more than 11 million times.It said print magazine subscribers will be able to upgrade their subscriptions to include digital editions at no additional cost.Time Inc. also said it has reached agreement with Barnes & Noble to sell digital subscriptions and single-copy issues of Fortune, People, Sports Illustrated and Time on the US bookseller\'s Nook Color electronic reader.Time Inc.\'s parent company Time Warner said Wednesday that net profit rose to $638 million in the second quarter from $562 million a year ago. Revenue was up 10 percent to $7.0 billion.