SAO PAULO, April 18 (Reuters) - Brazil's cotton exports will fall in the 2022/23 marketing year, an exporter group said, dashing hopes of the country surpassing the United States as the world's biggest exporter of the natural fiber as Brazilian buyers scramble or turn to alternative suppliers.

In an interview with Reuters on Monday, Miguel Faus, president of the National Association of Cotton Exporters (Anea), described a perfect storm slashing Brazil's first-quarter cotton exports.

From January to March, Brazil exported 243,000 tonnes of cotton, down 56% compared to the same period last year. In March alone, foreign sales fell by 59.2%, to 76,000 tons, official trade data showed on Monday.

"A reduction of this magnitude was not in the plans," said Faus. "It wasn't expected."

Anea now projects exports of 1.55 million tonnes for the 2022/23 commercial year, which started last July and ends in June, representing more than a 10% fall from last season. But even that may be optimistic, he said.

Brazil exported 1.725 million tonnes in 2022.

Faus said the situation reflects impacts of a financial crises in countries like Pakistan and Bangladesh, whose importers are struggling to obtain the letters of credit necessary to keep contracts with trading companies.

"Trading firms are the ones suspending shipments, because if the buyer doesn't have a letter of credit, you simply don't ship," Faus said. "Some contracts have been canceled too, a little bit of everything happened."

Turkey's earthquake in February also contributed to a decrease in shipments to the country and, in addition, there was a fall in purchases from key importer China.

"The Chinese are reducing shipments, buying from other origins... They increased their purchases of U.S. cotton a little and reduced ours," he said. (Reporting by Nayara Figueiredo; Writing by Ana Mano; Editing by Sandra Maler)