China Life Insurance Co., the country's top life insurer, has cooled towards mainland stocks despite reaping huge investment rewards in the first quarter, a senior executive said on Wednesday.

The company earned investment returns of 16.76 billion yuan ($2.2 billion) between January and March, nearly 40 percent of the levels it made in all of 2006.

"Now we are very cautious towards buying stocks. It is acceptable to see the index at three to four thousand points, but beyond that, we may not buy as actively as we did," Chief Investment Officer Liu Lefei told a news conference.

China's main stock index closed above 4,000 points for the first time on Wednesday as turnover ballooned to an all-time high.

Turning to China Life's expansion plans, Chairman Yang Chao said the company was actively looking for potential acquisition targets.

The firm was also in talks to bring in domestic or foreign strategic investors as a way of improving levels of corporate governance, he said.

Yang confirmed that the insurer was in talks to buy a stake in China Credit Trust Co. Ltd., a major domestic trust firm but said that a concrete agreement had yet to be reached.

Sources said last month that China Life had decided to buy a stake of more than 50 percent in China Credit Trust.

But the sources said the parties had not yet decided on whether China Life Insurance Group or its listed arm, China Life Insurance Co., would be involved in the deal.

Liu added that China Life was interested in the possibility of becoming a strategic partner of Agricultural Bank of China, the only Big Four state bank not to have been recapitalised by the government and to have floated shares.

Liu gave no details. ($1=7.7 yuan)