The merger between China's two largest train producers, CSR and CNR, is edging closer to completion.

It's been announced the merger will go under review by the China Securities Regulatory Commission tomorrow.

Shares of the two companies were once-again suspended this week from trading in Shanghai and Hong Kong.

This is common when two listed companies merge.

Meanwhile, it's being reported the current chair's and presidents of CSR and CNR will sit on the board of directors of the merged company, which is going to be called the China Railway Rolling Stock Corporation.

However, the precise role of the four executives has not been revealed.

Most industry observers expect the merger to be completed by June.