The visit is one element in a rapidly shifting business landscape in Iran as investors prepare for a lifting of the sanctions if a nuclear deal is signed in coming months between Iranian President Hassan Rouhani and world powers.

Rouhani’s election in 2013 on a reformist platform had already brought “a huge change of interest in Iran,” said Rouzbeh Pirouz, Harvard-educated chairman of Turquoise. “Now, with the prospect of the nuclear agreement, that interest has been much, much more.”

The group showed the outsiders the best-performing sectors in Iran: cement, which benefits from low energy costs; mobile telecommunications in a country of 80 million people with mobile phone penetration of 105 percent; and food and beverages, in which one firm, Behshahr Industrial Development Corp., quadrupled its profits over the past two years. Read more.