ExxonMobil Corp will need federal approval before it can restart its damaged North Line pipeline in Louisiana, where a leak in late April resulted in a spill of more than 1,800 barrels of crude, the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA) said on Wednesday. Exxon confirmed it had received PHMSA\'S corrective action order for the impacted section of the North Line and that it was in the process of reviewing the document. \"We will continue to work cooperatively with PHMSA and will provide a plan for their review prior to the restart of the line,\" said Claire Hassett, a spokeswoman for the company. \"It is still premature to speculate on when the full line will be restarted,\" she added. Exxon shut the 198-mile line on April 28 after a leak was discovered in an environmentally sensitive area along the coast. The 22-inch diameter North Line carries 160,000 barrels per day of crude oil -- mostly Heavy Louisiana Sweet -- from the Louisiana oil hub of St. James west into Texas via the MidValley pipeline. It serves Exxon Mobil\'s 502,000-bpd refinery in Baton Rouge, the nation\'s third-largest plant, as well as four smaller refineries. Subsequent excavation found a 17-foot-long rupture on the top of the pipe, which was constructed in 1956. An investigation is under way to determine why the pipe failed. Over last weekend, Exxon restarted the portion of the North Line that runs from St. James to Anchorage, Louisiana, near Baton Rouge on the eastern border of the state. Exxon had already restarted its South Line, which was shut in April for inspection. The line runs from Raceland northward to Anchorage. The PHMSA order means that Exxon will have to submit and win approval for a plan to restart the pipeline after repairs are completed. Under federal regulations, Exxon will have to gradually increase pressure on the line, making sure there are no leaks, before it can reach full throughput capacity.