FRANKFURT (Reuters) -Luxury sportscar maker Porsche AG on Tuesday said its operating margin fell to 8.6% in the first quarter, below analyst estimates, hit by weaker demand in China as well as U.S. import tariffs.

"The macroeconomic situation will remain challenging. We can't completely escape this, but we are doing everything within our power to counteract it," finance chief Jochen Breckner said.

First-quarter sales fell 1.7% to 8.86 billion euros ($10.08 billion), while the group's operating profit plunged 40.6% to 0.76 billion, said Porsche, which late on Monday cut its full-year outlook.

Analysts in an LSEG poll had, on average, expected an operating margin of 9.8% in the first quarter.

($1 = 0.8790 euros)

($1 = 0.8789 euros)