BEIJING, June 10 -- China's total enterprise annuity funds hit 2.98 trillion yuan (about 419 billion U.S. dollars) at the end of the first quarter of the year, official data showed.

In the first three months, the investment returns of enterprise annuity funds reached 44.02 billion yuan, with the weighted average rate of return standing at 1.55 percent, according to the Ministry of Human Resources and Social Security.

The country launched enterprise annuities in 2004 as a type of supplementary pension plan under which both employers and employees must contribute.

As of the end of March, a total of 133,512 enterprises and 30.59 million employees had joined such programs.