Atlantic Coast Pipeline LLC, a consortium of four energy companies that has proposed a 550-mile natural gas pipeline to bring energy to Virginia and North Carolina, announced an agreement Wednesday totaling more than $400 million with Dura-Bond Industries to produce steel pipe for the project. Pending approval by the Federal Energy Regulatory Commission , the Atlantic Coast Pipeline would run from Harrison County, W.Va., southeast through Virginia with a lateral extension to Chesapeake and then south through eastern North Carolina to Robeson County.