July 30 (Reuters) - The U.S. Treasury on Thursday said the

director of its anti-money laundering Financial Crimes

Enforcement Network, Andrea Gacki, was stepping down to join

Citigroup ( C ) as the bank's global head of sanctions.

Gacki is leaving government service after 25 years at the

Treasury and the Department of Justice and will remain at FinCEN

for several weeks to support a smooth leadership transition, the

Treasury said.

The department appointed career Treasury and former FBI

official Jenna Casanova as acting FinCEN director.