June 21 (Reuters) -
* Brazil's sugar and ethanol merchant Copersucar says Alvean, its joint venture with Cargill, increased sugar sourcing in Brazil adding volumes from independent sugar mills
* Brazil's Copersucar has not seen changes on sugar/ethanol production mix; says sugar still gives better returns
* Copersucar says sugar futures fall caused by expectations of large 2017/18 northern hemisphere sugar crop
* Copersucar says sugar trading JV Alvean could grow 4 or 5 percent more in volumes in the 2017/18 crop year
* Copersucar says U.S.-based subsidiary Eco-Energy trying to attract new ethanol suppliers to grow volumes
* Copersucar says there is risk of Brazil center-south mills not being able to crush all available cane this year due to excessive rains Further coverage: SUG