The New York Stock Exchange, the leading marketplace for exchange-traded funds, is losing ground to rivals in the fast-growing business.

For the first time in at least five years, NYSE Arca's ETF listings have declined from a year earlier, with more than 30 ETFs defecting this month for Nasdaq Inc. and Bats Global Markets. While NYSE Arca is still the industry leader, with 1,543 listings and $2.3 trillion in assets, the competition is intensifying following high-profile market failures last year and the departure of some of NYSE's top ETF talent.