Shares of BP plc (NYSE: BP) are down this morning after a major pipeline in Alaska was closed over the weekend due to a leak.

As of 9: 38 a.m. (EDT), BP shares have slipped 1.91 percent.

The Trans-Alaska pipeline system, which carries oil from the Prudhoe Bay field, transports about 12 percent of America's oil output.

BP is the biggest shareholder of the company which runs the pipeline.

A spokesman for BP categorized the leak as a significant event and did not say how long the closure would last.