More than 400 employees of private enterprises that were once collectively owned, protested Monday over endowment insurance payment in central China's Hubei Province.

The employees gathered at the gate of the Xiantao city government at about 9 a.m. They did not purchase endowment insurance when the formerly township-owned enterprises were privatized in the 1990s.

The employees said they were dissatisfied with a regulation released last year which said employees must each pay 30,000 yuan (4,395 U.S. dollars) or 26,000 yuan, before getting endowment insurance of 300 yuan or 260 yuan per month when they grew old.

Men would get their insurance after the age of 60 and women after 55.

The protesters started to leave the government gate at about 12:30 p.m. after talking with city officials who promised to investigate the situation and improve the social security regulation.

The workers selected five representatives to participate in the investigation.