WASHINGTON, Sept 21 (Reuters) - U.S. Defense Secretary Ash Carter, keen to expand the number of women and minorities in military leadership, on Monday will endorse "Lean In" discussion groups sparked by Facebook Chief Operating Officer Sheryl Sandberg's bestselling book, a senior defense official said.
Carter and Sandberg will meet at the Pentagon with 15 women from all ranks and military services who already lead Lean In groups, followed by a news conference, where Carter will promote creation of more such groups, at government facilities and even during working hours.
"If you look at the numbers, it's clear that we are not where we should be in terms of the leadership reflecting the overall force," said the official. "It's important that our force reflect the nation that it protects."
Lean In circles initially focused on helping empower women to tackle ongoing challenges in the workplace, but the organization this year encouraged men to get engaged as well.
In recent years, the Pentagon has stepped up its recruitment of women and minorities, and is moving to open more - if not all - combat jobs to women, a continuing source of debate among military and civilian leaders. Decisions are due this fall.
Women make up about 15 percent of the U.S. military, and thousands of women have served alongside men in Iraq and Afghanistan. But women also leave military service during the mid-career phase at twice the rate of men, and top military officials are seeking ways to retain them.
Carter and Sandberg - the author of "Lean In: Women, Work and the Will to Lead" - are due to hold a news conference at 1 p.m. (1700 GMT) to publicize their campaign.
The Lean In foundation - which says it now counts a total of 24,000 circles in 120 countries -- provides free material on its website for topics ranging from practical ways to counteract gender bias to principles of leadership.
Carter's public support of Lean In is part of his larger "Force of the Future" initiative aimed at bringing military workplace practices more in synch with changes in the civilian world, said the official.
"This has been a proven model for inspiring collaboration and helping people reach their professional goals, and he hopes that can be duplicated and broadened throughout the Department of Defense," the official said.
The defense official said some mixed gender groups were already meeting at the U.S. Naval Academy, where Sandberg has spoken and led Lean In circles several times. Sandberg has also worked closely with the U.S. Marine Corps.
U.S. Navy Commander Emily Bassett, executive officer of the USS Arlington, an amphibious U.S. Navy transport ship, says her Lean In circle of three years gives her a "lifeline of mentorship."
When the ship deploys to the Mediterranean in coming weeks, Bassett will be responsible for about 1,200 people from many diverse backgrounds, which can pose many daily challenges, she said.
"Just knowing I could call anyone in my Lean In group ... is a huge comfort to me. I don't ever feel alone. I know I could pick up the phone and say, 'How would you deal with this situation?' or 'Have you ever experienced this?" she said.
Bassett said she welcomed Carter's initiative and hoped it would encourage others to set up their own Lean In circles.
"What's important to me about Lean In, is that it's affecting the culture in the military to make it a safe, conducive place for women and men to talk about gender bias" and diversity, said Bassett, who has two children aged 4 and 6, and a stay-at-home husband. (Reporting by Andrea Shalal Editing by W Simon)