Cree’s act of filing lawsuits against Feit Electric and Unity Opto recently shows the firm’s struggle to maintain dominance in U.S. LED lighting market amid growing popularity of LED lighting products, according to a Bloomberg report.

Cree also accused Feit and Unity of false and misleading advertising. The firm claimed Feit lights do not met the requirement for Energy Star certification program but the company advertises the opposite. LED bulbs with Energy Star label are qualified for subsidies from local utilities that lower retail prices, which is crucial for sales.

Amid the U.S. Congress blocking rules to phase out the incandescent bulbs, LED bulbs has gained popularity among consumers as government subsidies drive the cost down. Statistics revealed that LED lighting sales volume went up around 60% last year and is expected to increase 34% this year, the report quoted Analyst Edwin Mok saying.

Cree announced was the first company to sell LED light bulb under $10 in U.S. last year to maintain its leading position in U.S. market against key players such as General Electric and Philips and emerging companies including Feit Electric.

LED lighting products have become Cree’s biggest sales and revenue source. Even though Cree’s sales grew 19% to US $1.6 billion in 2013, the firm’s stock fell 48% last year.

The shift of traditional bulbs to LED lighting has made a stir in the lighting industry. Earlier Osram laid off some 7,000 employees and some analysts have projected GE might sell its lighting division.