The first partners for the service will be Yahoo Japan and the news app Flipboard.
Because tweets are already embedded in those services, the new arrangement will allow advertisers to deliver promoted messages directly to users of those services.
"These new partnerships open a significant opportunity to extend the reach of their message to a larger audience," Twitter's Ameet Ranadive said in a blog post.
"Syndicated ads will be seen by users within Twitter content sections on third-party properties, as well as within third-party content areas."
The move allows an advertiser to run a simultaneous campaign on and off Twitter, Ranadive noted.
"Thousands of Web and mobile applications already syndicate Tweets to provide compelling content experiences, through products such as Fabric and Twitter for Websites," he added.
"Combine that with the flexibility and control of a promoted tweet, and we think marketers will have an almost infinite capacity to create large-scale, rich and well-targeted advertising campaigns across a variety of platforms. In a small number of private tests with Flipboard, both Flipboard and our advertising partners saw promising results."
Twitter, which unveils quarterly results this week, has been under pressure to show both revenue and user growth following its highly anticipated 2013 initial public offering.
Twitter is seeking to boost engagement with users amid growth which has been slower than some analysts have expected.
In October, Twitter said the number of monthly users grew 23 percent from a year earlier to 284 million.
A Pew Research Center report showed that among US users, Twitter is behind Facebook, Pinterest, LinkedIn and Instagram in the number of users.