Beijing also has opened the door wider for foreign investors to access the domestic bond market, though Chinese banks and mutual funds still make up the biggest chunk of buyers.

WSJ: China Probe Focuses on Trading of Bonds

Chinese companies' push into the bond market comes amid Beijing's efforts to wean businesses off bank loans and to build a competitive credit market that would better reflect the cost of capital.

WSJ: Faith in Bailouts Spurs China

Mark Follett, head of the firm's high-grade debt capital markets desk for Asia excluding Japan, says that is because many Chinese companies plan to tap the bond market and diversify their funding from a heavy reliance on bank loans.

WSJ: Asia's Bond-Market Growth Likely to Pause in 2013

The cleanup efforts come as Chinese companies are raising money in the domestic bond market at a record pace.

WSJ: China Probe Focuses on Trading of Bonds

"Starting from last year, Chinese corporate bonds, which were mostly sold to emerging-market bond funds in the past, have become much more appealing to U.S.-based bond investors, " said Fang Fang, vice chairman of Asia investment banking and chief executive of China investment banking at J.

WSJ: Higher Debt at China Oil Firms Could Slow M&A

Less than a month ago, a probe aimed at cleaning up trading activities in the bond market resulted in the arrests of several dealers and other fixed-income personnel at Chinese financial institutions.

WSJ: China Tightens Rules on Bond Issuance