BEIJING - China's largest trade union announced on Monday that it helped migrant workers claim 7.33 billion yuan ($1.19 billion) in unpaid wages in 2013.

Chen Hao, vice chairman of the All-China Federation of Trade Unions (ACFTU), made the remarks during a regular union meeting in Beijing.

Nearly one in five Chinese is a member of ACFTU, with union membership reaching 290 million this year, according to the organization.

Among the members of the ACFTU, the largest trade union in the world, a total of 110 million are migrant workers who come from rural areas and seek jobs in cities.

Wage delays have been a perennial headache for hundreds of millions of migrant workers, who often lack formal contracts and are sometimes left unpaid after their companies report low earnings or declare bankruptcy.

Chen said ACFTU stepped up efforts to protect the basic interests of workers in 2013 through preventing wage default, solving disputes involving overdue wages and making labor arbitration more efficient.