Economic activity rose 7.95 percent in November compared with the same month last year, below the 8.26 percent rate notched in October.
The finance ministry projects Panama's $33 billion economy expanded 8.5 percent last year.
Though the economy is stepping back from the double-digit growth Panama has posted in four of the past six years, it is still one of the fastest-growing in the region.
The growth is spurred by massive infrastructure spending, including the ongoing expansion of the Panama canal, which began in 2007, and the $1.8 billion construction of Central America's first metro rail system.
But since the start of 2014, the Panama Canal Authority has been embroiled in a public row with the consortium known as Grupo Unidos Por el Canal over $1.6 billion in added costs the GUPC says have arisen during work on the project.