* Boy Scouts had affirmed anti-gay policy in July 2012
* National Board meets Monday-Wednesday in Texas
* Youth membership down 21 percent since 2000 (Adds details on delivery of petitions to Boy Scouts)
By Marice Richter
DALLAS, Feb 4 (Reuters) - Boy Scouts of America board members opened a three-day meeting on Monday in which they will consider ending a controversial national ban on gay membership, sparking a flurry of lobbying from groups both for and against the change.
The national executive board, which lists more than 70 members, is expected to vote on Wednesday on whether to lift the ban they had reaffirmed just last year amid criticism from gay rights groups and gay former Scouts and Scout leaders.
The meeting at a hotel near Boy Scouts headquarters in Irving, Texas, is closed to the public.
The organization said late last month it was considering removing the national restriction based on sexual orientation and leaving the decision to local chapters. It said it would not dictate a position to units, members or parents.
Gay rights activists have said it is not enough to lift the national ban but allow local units to maintain a ban.
The board meeting comes as the century-old youth organization that prides itself on teaching boys life skills such as camping and leadership faces membership declines and a donations boycott by some corporations over its anti-gay policy.
Youth membership in the Boy Scouts has dropped 21 percent since 2000 to nearly 2.7 million. Adult leader membership has fallen 14 percent to just over 1 million, and the number of units has declined 12.6 percent to 108,971.
Activists have pressed corporations, including Merck and UPS, as well as the Intel Foundation to withhold contributions to the Boy Scouts while the ban stands.
The Boy Scouts has also faced criticism for keeping from public view files covering decades of reports of child sex abuse in the organization. It released thousands of pages of files covering 1965 to 1985 in October under a court order.
The drive to lift the ban gained a powerful ally on Sunday in President Barack Obama. In an interview with CBS, anchor Scott Pelley asked the president if he believed scouting should be open to gays, Obama said: "Yes."
"My attitude is ... that gays and lesbians should have access and opportunity the same way everybody else does, in every institution and walk of life," said Obama, who last year gave his backing to the right to same sex couples to marry.
"The Scouts are a great institution that are promoting young people and exposing them to, you know, opportunities and leadership that will serve people for the rest of their lives, and I think that nobody should be barred (from) that."
Texas Governor Rick Perry, an Eagle Scout, told reporters Saturday he did not see a reason for the Boy Scouts to change its policy, the Austin American-Statesman reported.
PARENTS, CHAPTERS DIVIDED ON BAN
Parents are also split on the proposal. Pam Bakowski, the mother of an Eagle Scout and former den leader and Cub master who lives in the Dallas area, said the Boy Scouts were about teaching life skills and leadership.
"I think the ban is ridiculous and needs to be lifted," Bakowski said.
The mother of an Eagle Scout, who asked to be identified only by her first name, Denise, said she opposed the change.
"The current policy has worked fine for more than 100 years so there is no reason to change it," she said. "If my son had been in a troop with a gay leader, I would have taken him out."
The Boy Scouts won a 5-4 U.S. Supreme Court ruling in 2000 that upheld the organization's ban on gays, but it has come under increasing public pressure in recent years from activists.
The faith-based groups that have the most Boy Scouts youth members - the Mormon church, the United Methodist Church and the Catholic Church in that order - have so far stood by the Scouts.
Many local chapters have said they were waiting for the national board to render a verdict before weighing in. Others want board members to take more time to consider a decision.
Activists on both sides of the issue urged supporters to lobby board members before the meeting and plan demonstrations at Boy Scouts headquarters this week.
"Save our Scouts" plans a prayer vigil in support of the ban for Wednesday morning to coincide with the expected vote.
Gay rights activists delivered four boxes of petitions totaling more than 1.4 million signatures in support of lifting the ban to Boy Scouts headquarters on Monday.
"We've previously met with these individuals and accepted this petition," Boy Scouts spokesman Deron Smith said in a statement. "The BSA has received a great deal of feedback from a variety of viewpoints and we appreciate everyone sharing their perspective on this issue."
The activists who delivered the petitions included Jennifer Tyrrell, a lesbian mother from Ohio who was ousted as a Scout den leader, and Greg Bourke, a former assistant Scoutmaster from Kentucky who was removed from his position because he is gay.
Two board members have said publicly they support change. Jim Turley, chairman and chief executive of Ernst & Young, has called for ending the ban and AT&T CEO Randall Stephenson has said he favors change from within and supports diversity. (Additional reporting and writing by David Bailey in Minneapolis; Editing by Tim Gaynor, Christopher Wilson, Cynthia Johnston and Andrew Hay)