CNN

Sen. Barack Obama wins a major endorsement Wednesday.

(CNN) – The United Mine Workers of America endorsed Barack Obama's White House bid Wednesday.

"We are extremely proud to make this endorsement today," UMWA International President Cecil Roberts said. "Sen. Obama shares the values of UMWA members and our families. He understands and will fight for the needs our members have today and the hopes our members have for a secure future for themselves and their families."

The UMWA says it represents 105,000 active and retired coal miners, mine construction workers, public service employees, health care workers and manufacturing workers in the United States and Canada, and that its membership includes more coal miners than any other union in the world.

The unanimous endorsement by the union’s political action committee comes shortly after the May 13 primary in West Virginia - a large coal producing state. Hillary Clinton overwhelmingly won that primary, 67 percent to Obama's 26 percent.

Roberts said the union considered both Sens. Obama and John McCain before making the decision, but found that Obama "will be on our side while Sen. McCain will not," citing proposals supported by the presumptive Republican nominee that he claimed would cut jobs in coal country, particularly in the Eastern area.

UMWA International's Dan Kane said the union will be "working as hard as we can, using every resource at our disposal in every community where our members live and work across this nation to do our part to help [Obama]."

Last week, Obama picked up the backing of the United Steelworkers Union. Both the Steelworkers and UMW had originally backed former Democratic presidential candidate John Edwards, who endorsed Obama last week.