Ask the search engine Ecosia about “Paris to Prague” and flight booking websites dominate the results. Ecosia’s CEO, Christian Kroll, would prefer to present more train options, which he considers better for the environment. But because its results are licensed from Google and Microsoft’s Bing, Ecosia has little control over what’s shown. Kroll is ready for that to change.

The Berlin-based company, which donates its profits to tree planting, and its Paris-based competitor Qwant are announcing Tuesday that they will team up to develop an index of the web.

The for-profit joint venture, dubbed European Search Perspective and located in Paris, could allow the small companies and any others that decide to join up to reduce their reliance on Google and Bing and serve results that are better tailored to their companies’ missions and Europeans’ tastes. “We could derank results from unethical or unsustainable companies and rank good companies higher,” Kroll says of the eco-minded Ecosia.