Monte Cristo announced that they will shut down the online component of Cities XL due to low subscription numbers. It seems they will concentrate on the single player experience and release from time to time new content packs, while working on a single player sequel Cities XL 2011.

Dear Mayors,

First of all we want to thank you for your support since Cities XL was released in October of last year, and as far back as October 2007 for some of you.

In early 2007 we decided to be those who would make a new offer to City Builder games fans. Right from the start Cities XL has always been an innovative project regarding its online dimension. Of course, trying something new always comes with a risk.

Three months after the launch we have to admit that the subscription rate is lower than what we expected and therefore the Planet Offer is no longer sustainable. Not enough players decided to subscribe.

Therefore, it is with deep regret that we decided to put an end to the Planet Offer on March 8^th 2010. It will no longer be possible to subscribe to the game starting Monday February 1^st 2010.

Nevertheless the Cities XL adventure goes on! Cities XL will evolve into a fully single player game. As soon as march the Bus will be added for free in the solo game. At the same time we also keep on working on new content and new features to keep on improving Cities XL.

We do realize that some of you were real fans of the Planet Offer, and loved to be able to visit other player’s cities and trade tokens between each other. There are simply not enough of us.

Thank you again for your understanding and support.

For more detailed information, you can read the FAQ here.

Source:   http://www.citiesxl.com/index.php?option=com_content&task=view&id=3498&Itemid=128