China's SAIC Motor Corp has agreed to take a stake in General Motors Co if Chinese regulators approve a deal to deepen an existing alliance between the two auto makers, sources familiar with the matter said.

The potential investment from SAIC is part of a surge in investor interest in GM that is expected to push the pricing of its shares to US$29 or above in the US auto maker's initial public offering, one of the sources said.

Another source said SAIC, GM's partner in China, would take a stake of around 1 percent in the car maker, majority owned by the US Treasury after a bailout last year.

An investment of just over US$500 million would represent about 1 percent of the common stock in GM if the IPO prices at the high end of the proposed range this week.

SAIC was also taking part in the deal to gain access to GM's sales networks outside China.