UPDATE 2-US agency proposes change for airline union votes

* NMB proposes union polls based on majority of votes cast

* Airlines oppose rule change, unions favor

* AFL-CIO says current procedure unfair (Adds Delta, union comment)

ATLANTA, Nov 2 (Reuters) - The U.S. National Mediation Board has proposed a sweeping rule change that would base the outcome of union elections at airlines and rail companies on the majority approval of people who vote, a move that could increase the odds of unions winning such contests.

The proposal, if implemented, would change current procedures dating back 75 years that require a majority of an entire work group to approve unionization. That policy effectively counts members of a group who don't vote as 'no' votes.

"It's a good turn for unions because it makes the election process fairer and it resembles more closely national political elections," said Gary Chaison, professor of industrial relations at Clark University in Worcester, Massachusetts.

In its proposal, posted to a government website on Monday, the mediation board said the current procedure under the Railway Labor Act seems "at odds" with basic tenets of democratic elections.

"The NMB believes that this change to its election procedures will provide a more reliable measure/indicator of employee sentiment in representation disputes and provide employees with clear choices in representation matters," the board said in the proposal. ENCOURAGE VOTER PARTICIPATION

The proposal added that the change would discourage worker non-participation in union elections.

The chairman of the three-member mediation board, Elizabeth Dougherty, disagreed with the rule change, saying it would be "an unprecedented event" in the labor board's history. She added there was a question as to whether the NMB had the "statutory authority" to reverse the current policy.

Edward Wytkind, president of the Transportation Trades Department of the AFL-CIO, which requested the rule change in September, said union elections should be decided based on the will of those who vote.

He added that pressure or intimidation from company management leads many people to abstain from voting in union-organizing elections. He said the current system that in practice counts abstentions as 'no' votes assigns voter intent where it has not been expressed.

"For the airlines, it will never be a convenient time to change a status quo that favors them so heavily," Wytkind told reporters during a conference call. "But for the workers who have been facing an unfair standard for too long, change cannot come soon enough."

The change, if implemented after a 60-day comment period, could have nearer-term implications for Delta Air Lines Inc (DAL.N), where the Association of Flight Attendants-CWA and the International Association of Machinists and Aerospace Workers unions have sought elections to represent certain employees.

Atlanta-based Delta was largely non-union before it acquired Northwest Airlines a year ago, and union representation must still be resolved for tens of thousands of workers. Union victories could lessen the airline's ability to control costs as drooping travel demand hurts profitability.

"This will be the closest union election vote at Delta and this rule change could well swing the outcome," said Bruce Kaufman, a professor at Georgia State University's Andrew Young School of Policy Studies who specializes in labor economics and human resource management.