(Reuters) - Berkshire Hathaway ( BRK/A )-owned BNSF Railway said on Thursday it has reached a tentative agreement, for a five-year deal, with the International Association of Sheet Metal, Air, Rail and Transportation Workers (SMART) union.

The agreement, which still needs to be ratified by the union members, provides a 3.5% average wage increase per year over the next five years, including improvements in healthcare benefits and provisions that offer railroaders more vacation days earlier in their career.

The contract covers members of the union's transportation division (SMART-TD), including Yardmasters.

"The news marks eight tentative agreements in less than one month's time, representing more than 15,000 employees and more than 46 percent of BNSF's union workforce," the railroad said.

In August, BNSF reached tentative agreements with four labor unions in partnership with its peer Norfolk Southern ( NSC ) .