Complex sentence: On June 15,2011, BNSF and Amtrak announced reaching an agreement to each cover one-third of the cost of rebuilding the rail line, with the United States Government covering one-third.
Split into simpler sentences: On June 15,2011, BNSF and Amtrak announced reaching an agreement to rebuild the rail line. Each would cover one-third of the cost, and the United States Government had agreed to cover one-third.