Samsung Electronics Co Ltd reported on Friday its sixth straight quarter of profit growth ahead of the sale of the Galaxy S4 smartphone this weekend, its biggest assault on rival Apple Inc yet.

The South Korean IT giant said January-March operating profit increased 54 percent from a year ago to 8.8 trillion Korean won ($7.91 billion), broadly in line with its estimate.

With the S4, Samsung is taking aim at the U.S. market, Apple's turf, as the iPhone maker reported its first profit decline in more than a decade. Apple also indicated no major product releases until the fall.

This week, Samsung kicked off a massive advertising campaign and set up mini stores at Best Buy locations ahead of the S4's debut in the United States. ($1 = 1112.2250 Korean won)

(Reporting by Miyoung Kim; Editing by Ryan Woo)