
Dennis is looking to increase sales and boost the brand name of The Week, its weekly compendium of news stories, which has been a hit with readers since its 1995 launch in the UK.
Prosper will be sent out free to more than 150,000 subscribers of The Week twice a year.
Dennis denied that it had plans to launch the bi-annual as a standalone paid-for title, if it receives positive feedback from readers.
The title will provide readers with an investment guide to the world of finance in a tie-up between Dennis and MoneyWeek Limited, the publisher of MoneyWeek.
Dennis previously published MoneyWeek, but sold it to Finance News Ltd in 2002. The title was then purchased by US finance publisher Agora, the parent company of MoneyWeek, in 2003.
Prosper's editorial content will be headed by MoneyWeek editor John Stepak.
The launch issue, out next month, has features on why the clever money is going into Japan, how to pick a private bank, and the best way to invest in the current gold rush.
Kerin O’Connor, managing director of The Week, said: "We are delighted to diversify our editorial offering to The Week’s readers by launching Prosper. With so much financial information out there, sifting out the right insights and working out the best advice can be hard at the best of times. Prosper has been developed to provide smart, relevant and profitable editorial for our growing army of wealthy readers."
The Week gained 9.8% year on year in the latest ABC round-up, to reach an average issue circulation of 169,690 copies. MoneyWeek was up 10.4% year on year. to 42,953 copies for the July to December 2009.