Nebraska ? Warren Buffett’s company completed its largest acquisition ever Friday when it bought Burlington Northern Santa Fe Corp.

Berkshire Hathaway Inc. also joined the S&P 500 and S&P 100 stock indexes after Friday’s close of the markets because as part of the BNSF deal, the Omaha-based company gained liquidity by issuing new shares and splitting its Class B shares 50-for-1. The deal also created an opening in the S&P indexes because Berkshire bought one of the nation’s largest railroads.

The stock index news helped Berkshire’s stock post significant gains since it was announced Jan. 26.

Berkshire Hathaway Inc. paid roughly $100 per share in cash and stock for the 77.4 percent of BNSF shares that it didn’t already own.