By Marice Richter

DALLAS (Reuters) - Boy Scouts of America board members on Wednesday delayed until May a vote on whether to end a longstanding and controversial ban on gay membership.

The century-old youth organization had been expected to vote on the matter at a board meeting in Dallas on Wednesday. The Boy Scouts upheld the ban just last year but faced sharp criticism from gay rights groups.

"After careful consideration and extensive dialogue within the scouting family, along with comments from those outside the organization, the volunteer officers of the Boy Scouts of America's National Executive Board concluded that due to the complexity of this issue, the organization needs time for a more deliberate review of its membership policy," the Boy Scouts said in an emailed statement.

In the interim, the board will continue its consultations with other scouting representatives and will take up the matter at its national council meeting in May.

The Boy Scouts touched off fierce lobbying by groups both for and against changing the policy when it said late last month that it was considering removing the national restriction based on sexual orientation and leaving the decision to local chapters.

The national executive board, which lists more than 70 members, has been meeting privately since Monday at a hotel near Boy Scouts headquarters in Irving, Texas. The Boy Scouts released no details about the deliberations on Tuesday.

Many local chapters have said they were waiting for the board to render a verdict before weighing in, and a coalition of 33 councils that represent about one-fifth of all youth members has asked the board to delay the vote for more study.

(Additional reporting by Dan Burns, Dan Trotta and David Bailey; Editing by Cynthia Johnston, Cynthia Osterman and Nick Zieminski)