QUITO, April 11 (Reuters) - Opposition by indigenous communities in Ecuador is holding up some $1 billion of investments for constructing three mining projects in the South American country, an executive of the Ecuadorean Chamber of Mining said on Tuesday.

Ecuador's largest indigenous organization, CONAIE, last month asked the country's top court to annul a government decree that sets parameters for community environmental consultations.

While such consultations are needed before Ecuador's environment ministry can issue environmental licenses for mining and oil projects, indigenous communities are pushing instead for an earlier say on whether the project should proceed at all.

CONAIE has said the current consultation parameters could actually accelerate the development of mining projects.

Maria Eulalia Silva, president of the Ecuadorean Chamber of Mining, called on judges in the Constitutional Court to reject CONAIE's request.

"These types of actions ... have real implications in the lives of Ecuadoreans," Silva said, adding that communities living near mining projects have benefited from them.

Investments planned for constructing mines over the next two years has been held up, she added.

The affected projects include Canada's Adventus Mining Corp's Curipamba copper-gold development, Atico Mining Corp's gold-rich La Plata project, and Dundee Precious Metals Inc's Loma Larga copper-gold development.

Ecuador's ministry of energy and mines and CONAIE did not respond immediately to requests for comment.

Ecuador has abundant mineral reserves but has lagged behind regional neighbors such as Peru and Chile in large-scale mining development.

A local court recently ruled that communities living in the highly biodiverse Intag region of Ecuador, located in the Imbabura province, had been denied their rights to environmental consultation ahead of building the Llurimagua copper project, forcing advanced exploration activities to be suspended.

The government of conservative President Guillermo Lasso has pledged to increase mining development to help Ecuador's struggling economy. Mining exports grew 32.6% to $2.76 billion last year. (Reporting by Alexandra Valencia; Writing by Oliver Griffin; Editing by Jamie Freed)