(Reuters) - Solar panel maker First Solar ( FSLR ) forecast higher current-year sales, and posted a rise in fourth-quarter profit on Tuesday, and said it has initiated legal action against JinkoSolar ( JKS ) for patent infringement.

Shares were up 3.8% $153.00 in extended trading.

The Biden administration had imposed a round of tariffs on solar panel imports from four Southeast Asian nations in November, after American manufacturers complained companies were flooding the market with unfairly cheap goods, benefiting U.S. companies such as First Solar ( FSLR ) that produce domestically.

Solar-generated electricity is one of the fastest-growing segments of the U.S. energy industry due to strong demand from corporations and governments to adopt cleaner sources of power and combat climate change.

The company reported a net income of $393 million for the quarter ended December 31, up about 13% from last year.

Separately, the company said it has initiated legal action against Shanghai-based JinkoSolar ( JKS ) for infringement of TOPCon, a technology which improves efficiency of solar panels, patents in the United States District Court of Delaware.

First Solar ( FSLR ) had obtained the patents from the acquisition of TetraSun in 2013.

"Our interaction with JinkoSolar ( JKS ) has been unproductive and left us with no choice but to enforce our patent rights through legal action," said Executive Vice President Jason Dymbort.

First Solar ( FSLR ) now expects current-year sales between $5.3 billion and $5.8 billion, the mid-point of which is about 32% higher than last year and also above Wall Street estimates of $5.52 billion, according to data compiled by LSEG.