WARSAW, May 29 (Reuters) - Poland's KGHM said it was delaying the start of copper concentrate production at the Afton-Ajax open-pit mine in Canada to end-2018 from an initial target of 2015 after it consulted with local residents and decided to expand the project.

Europe's second-largest copper producer took over the old mine site in British Columbia in 2012 and plans to invest $795 million to develop and operate it. Canadian firm Abacus is a local partner in the project.

Although a 2012 feasibility study mentioned a start date of 2015, KGHM already at that time expected the plan would be delayed, a KGHM spokeswoman said on Thursday.

"We knew from the very beginning that sticking to this timing was not our priority. The project has been enlarged, and we also wanted to talk to local people as we're a socially responsible company," the spokeswoman said.

"The revised schedule assumes that construction of the mine will start in the middle of 2016, which means a delay in capital investment," KGHM said in a statement.

The company forecasts annual production will ultimately amount to 50,000 tonnes of copper concentrate and 100,000 ounces of gold.

(Reporting by Marcin Goclowski; editing by Jane Baird)