DUBAI, United Arab Emirates — Iran’s Revolutionary Guard faces a new enemy: the gradual opening of the country’s economy after the nuclear deal with world powers.

Though better known for its hard-line fervor as an elite force created to defend Iran’s cleric-led system, the Guard holds vast business interests both public and hidden across the Islamic Republic.

In times of international sanctions, the organization won massive no-bid government contracts and expanded its influence.

But comments made by one Guard general about a new ship deal worth $650 million betray the worry felt in the organization over potential competition, analysts say. It also offers a possible secondary motive for its detention of dual nationals on purported espionage charges and its confrontations with the West: keeping its share of Iran’s market of 80 million people.

“They are worried about competition internally,” said Alireza Nader, an analyst at the RAND Corporation who long has studied the Guard. “They want to make sure for any given deal, they get a part of it.”

Last Friday, the Islamic Republic of Iran Shipping Lines Co. signed a deal with South Korea’s Hyundai Heavy Industries for 10 container ships. It marked the first deal with a foreign shipbuilder since the nuclear accord that limited Iran’s enrichment of uranium in exchange for the lifting of some international sanctions.