(Bloomberg) — The New York Stock Exchange shut down its main market because of a computer malfunction, forcing traders to steer orders elsewhere in the biggest disruption to an American equity venue in almost two years.

The suspension, announced to securities firms through notices on the NYSE website around 11:32 a.m., dropped the largest U.S. share platform out of the network of trading platforms that make up the American equity market. That network kept running, however, as other exchanges such as the Nasdaq Stock Market and Bats Global Markets Inc. picked up the runoff.

"We're currently experiencing a technical issue that we're working to resolve as quickly as possible," Marissa Arnold, an NYSE spokeswoman, said in an e-mailed statement. "We will be providing further updates as soon as we can, and are doing our utmost to produce a swift resolution, communicate thoroughly and transparently, and ensure a timely and orderly market re-open."