June 20 (Reuters) - U.S. firm Fulcrum LNG was selected to help Guyana develop a plan to design, finance, construct and operate a natural gas processing facility in the South American country, President Irfaan Ali said on Thursday.

The company's proposal was selected from among 17 submitted to Guyana for the gas project. Fulcrum will work with Guyana and energy giant Exxon Mobil, which leads a consortium responsible for all the country's oil production, President Ali said at a media briefing.

"We have identified a technical team to work with the stakeholders in coming up with the model and to negotiate a heads of agreement and look at the viability -technically and financially- of the project," Ali said.

An Exxon Mobil spokesperson did not have an immediate comment on the announcement. (Reporting by Kemol King in Georgetown; writing by Gary McWilliams)