Strikes cost South Africa 6 billion rand ($453 million) in wages in 2014, lower than the previous year despite a record five-month strike in the mining sector, a report published by the Department of Labour showed on Monday.

In its annual report on strikes in Africa's most advanced economy, the department found they cost the country last year 9 percent less than the 6.7 billion rand recorded in 2013.

Last year South Africa's economy was sapped by the record five-month platinum mining strike, pushing it into a quarterly contraction while a four-week manufacturing strike further hobbled economic activity.

The Association of Mineworkers and Construction Union led the wage strike at operations of the world's top producers, cutting output by 44 percent and was responsible for 92 percent of the lost working days in strikes across the country.

The National Union of Metalworkers of South Africa, the biggest by membership, downed tools for four weeks over pay in the sector accounting for 2.59 percent of the lost working days in 2014.

Measures by companies to cut labour costs and reduce salaries while reporting an increase in earnings, executive pay and exporting profit was seen as increasing the wealth and income inequality in society, the report said.

"The industrial action, in particular their length of period by workers was the reflection of the desperate situation, method of resistance and struggle for increased income to maintain and improve the living conditions of their families."

To limit the impact of strikes, new laws effective from April allow the government to intervene in labour disputes by limiting prolonged strikes while the labour department has suggested implementing a national minimum wage.