The survey compiled nearly 40 different items of financial data for about 39,000 companies in China, including local companies and Chinese subsidiaries of foreign companies. The companies come from a broad range of sectors within the tech industry, from those that make fire-safety products to makers of more typical high-tech goods such as mobile phones and personal computers.

The survey suggests that Chinese tech companies are gaining ground on multinationals in terms of size and in terms of the efficiency of their operations, as they learn to fine-tune processes that in the past relied strictly on China's abundance of cheap labor to compete. It also found that Chinese tech companies are increasingly moving up from low- and midprice product segments, which they have long dominated, into higher-end product segments that foreign companies have long dominated.

"This is a major wake-up call for multinationals," said Ingo Beyer von Morgenstern, the Shanghai-based McKinsey director who oversees the firm's technology practice in Asia.

Several Chinese tech companies, such as PC vendor Lenovo Group Ltd. and telecommunications-equipment giant Huawei Technologies Co., have begun competing in foreign markets. Mr. Beyer von Morgenstern said the survey's results suggest that many other Chinese companies that have grown largely "under the radar" of their foreign competitors are likely to follow suit.

One of the survey's more unexpected findings was that privately owned Chinese companies have sharply increased their productivity, as measured by revenue per worker, to levels that match or exceed their foreign counterparts, McKinsey executives said. Improved productivity enables companies to expand more quickly and can lead to greater profitability.

The survey doesn't reveal why Chinese companies have been able to make such gains in productivity relative to their foreign counterparts.

To sign up for The Wall Street Journal Briefing please visit http://www.briefing.wsj.com/hktdc.