The phrase "a leading export" is correct and usable in written English.
It can be used to describe a product or commodity that is among the top exports of a country or region.
Example: "Coffee is a leading export of Brazil, contributing significantly to its economy."
Alternatives: "a top export" or "a major export".
This week the head of a leading export trade group warned that the overvalued currency and hot money flows would lead to financial ruin.
Santos is a leading export outlet for sugar and coffee.
American education, especially higher education, is a leading export by attracting foreign students to the US.
A leading export for New York is digital content, but the industry is heavily burdened by theft --reducing the profitability of exports.
Entertainment is a leading export from the U.S. and if this is what is being exported, then the views of the 1% and not democracy, are what people will be seeing for years to come.
Chinese leaders are alarmed by the prospect of a deep recession in leading export markets at a time when their own economy, after a long streak of double-digit growth, is slowing.
* Southern New Jersey: You are to figure out how we reconcile our newfound honorableness with the fact that our leading export, a certain television show, is based on the glorification of organized crime.
After Dacko set up a diamond cutting factory at Bangui, diamonds became the country's leading export.
Slavery, an economic necessity in the new America, where cotton was the leading export and slave labor made the plantations possible, could be viewed as an act of mercy.
Brazil, once thought of as just an agricultural exporter, now counts airplanes and automobiles and car parts as its leading export items.
They might well be that country's leading export.
