South Korea will ease visa requirements for Chinese tourists, in a bid to attract more visitors from its neighboring country that have emerged as the major customers of its tourism market, the justice ministry said Tuesday.

The subjects eligible for issuance of multiple-entry visas will expand starting August 1 to include employees of China's top 500 companies, schoolteachers, retirees with pension income, holders of various professional licenses and graduates of prestigious colleges, the ministry said.

The multiple-entry visa would allow them to freely enter South Korea for up to three years, it said.

Currently it is offered only to those with permanent residence in member countries of the Organization for Economic Cooperation and Development, owners of platinum or gold-class credit cards and professionals like professors and doctors.

South Korea will also issue "double-entry" visas that would allow Chinese to enter the country twice within a set period for tourism.

There has been a rapid growth in the number of Chinese tourists visiting South Korea in recent years. There were 1.2 million Chinese visitors in 2009, significantly higher than 585,567 in 2005, according to the ministry.

The South Korean government aims to attract some three million Chinese tourists annually from 2012.