A Seoul appeals court on Friday annulled the dismissal of 153 former employees of Ssangyong Motor Co. who were part of the company's mass layoff plan in 2009.

Overturning a lower court's decision to rule in favor of the country's smallest carmaker, the Seoul High Court declared invalid the management's decision and ordered the reinstatement of the former employees.

"The court deems that the (management) did not make enough efforts to avoid the layoffs," judge Cho Hae-hyeon said in his ruling.

The plaintiffs, who have been fighting a legal battle for nearly four years, will be able to return to their workplace if the ruling is upheld by the nation's top court.

Ssangyong cut 2,646 jobs, approximately 37 percent of the total workforce, in April 2009 after it was put under court receivership in the aftermath of the 2008 global financial crisis.

The layoff sparked a 77-day-long strike by 5,500 unionists at the company's factory in Pyeongtaek, some 70 kilometers south of Seoul. Some 1,700 employees chose to retire, while 164 were dismissed and 455 were forced to take unpaid leave.

In 2012, the company agreed with its union to reinstate the workers who had been on unpaid leave, saying its financial status has improved to the point where it can embrace the workers as its sales were recovering and deficit was narrowing.

However, the retired and dismissed workers were not subject to the reinstatement plan.

The carmaker is now owned by Indian automotive group Mahindra & Mahindra, which acquired Ssangyong Motor from Chinese automobile manufacturer Shanghai Automotive Industry Corp. in 2010. (Yonhap)