Maryland’s largest LGBT advocacy organization on Monday announced it has endorsed Lieutenant Gov. Anthony Brown for governor in an apparent snub of lesbian state Del. Heather Mizeur (D-Montgomery) who is seeking the same office.

“We are proud to put our support behind the Brown/Ulman ticket for governor and lieutenant governor,” said Equality Maryland Executive Director Carrie Evans in a statement. “After meeting with the three declared Democratic candidates, we believe that Anthony Brown and [Howard County Executive] Ken Ulman will be the most effective governor and lieutenant governor for Equality Maryland’s issues and for the citizens of Maryland.”

Brown stressed his ticket’s ongoing support of marriage rights for same-sex couples and other LGBT-specific issues in a statement after Equality Maryland announced it’s endorsement.

“We’ve made great progress over the past seven years, achieving marriage equality and strengthening domestic violence services for LGBT residents, while working to ban discrimination based on gender identity,” he said. “Ken Ulman and I are committed to maintaining Maryland’s position on the right side of history at the forefront of the fight for equality, and we support all Marylanders and their families.”

Mizeur described the Brown endorsement as a “puzzling choice” in a statement.

“No one in this race has done more for the LGBT community than the Mizeur-Coates ticket,” she told the Washington Blade. “I’m not sure what more we could have done to earn their support.”

Evans defended her organization’s decision to endorse Brown — and not Mizeur.

“I suppose any candidate that doesn’t get an endorsement feels snubbed,” Evans told the Blade. “Equality Maryland is confident the Brown/Ulman administration will provide the leadership Equality Maryland needs in our next governor and has the relationships we need to move LGBT issues forward in our state.”

Brown will face off against Mizeur and Attorney General Doug Gansler in June’s Democratic primary.

Gansler in 2008 became the first statewide official to back marriage rights for same-sex couples in Maryland when he testified in support of the issue during a state Senate committee hearing. Both he and his running mate, state Del. Jolene Ivey (D-Prince George’s), and Mizeur are among the elected officials who attended Equality Maryland’s 25th anniversary brunch in Baltimore in October.

EMILY’s List earlier this month announced it would encourage its members to contribute to Mizeur’s campaign.

The Montgomery County Democrat in November tapped Rev. Delman Coates of Mount Ennon Baptist Church in Clinton as her running mate. Coates in February 2012 emerged as one of Maryland’s most prominent same-sex marriage supporters after testifying in support of a bill that would allow gays and lesbians to legally marry in the state.

Mizeur would become the country’s first elected openly gay governor if voters elect her to succeed Gov. Martin O’Malley.

Equality Maryland also announced it has endorsed state Sen. Rich Madaleno (D-Montgomery County) and state Del. Luke Clippinger (D-Baltimore City). The statewide LGBT advocacy group said in a press release that it’s political action committee will announce at least one more round of endorsements in the coming months.

“Equality Maryland’s PAC has worked since 2006 to help elect individuals who will fight for LGBT equality,” said Equality Maryland PAC Chair Tim Williams. “it is remarkable that seven years later, we have come to a point where all three Democratic candidates for governor are enthusiastically supportive of LGBT issues.”