Sen. Brian E. Frosh (D-Montgomery), left, speaks with Sen. Joan Carter Conway (D-Baltimore) during a special legislative session on congressional redistricting in 2011. (AP Photo/Patrick Semansky)

Sen. Brian E. Frosh is set to pick up another labor endorsement in his bid to become Maryland’s next attorney general.

AFSCME Maryland Council 3, which represents about 25,000 state employees and public university employees, plans to formally announce its support of Frosh (D-Montgomery) at a rally Saturday morning in Baltimore.

Frosh, the chairman of the Senate Judicial Proceedings Committee, previously won the endorsement of the Maryland-D.C. AFL-CIO Council, the umbrella organization for labor in the region.

Frosh faces three other Democrats in the June primary: Dels. Aisha N. Braveboy (D-Prince George’s), Jon S. Cardin (D-Baltimore County) and C. William Frick (D-Montgomery).

No Republicans have announced candidacies in the race to succeed Attorney General Douglas F. Gansler (D), who is running for governor.