TOKYO (Kyodo) -- Over half of major Japanese firms said they are prepared or are making preparations for a potential Chinese invasion of Taiwan amid Beijing's growing military assertiveness, a Kyodo News survey showed Saturday.

Of the 114 companies surveyed between late November and mid-December last year, 53 percent said they had concrete measures in place for a potential Taiwan contingency, including drafting manuals, planning evacuations, and stockpiling inventory.

Another 12 percent said they did not have plans but saw the need for consideration, according to the survey, which covered a range of industries and included companies such as Toyota Motor Corp. and ANA Holdings Inc.

The survey results highlighted how growing tensions between China and Taiwan are seen as a high-risk factor in running businesses.

Communist-ruled China and Taiwan have been governed separately since they split due to a civil war in 1949. Beijing views the self-ruled island as a renegade province that is to be unified with the mainland, by force if necessary.

Toshiya Tsugami of the Japan Institute of International Affairs praised the firms for their preparations but expressed concern that some may decide to "take excessive actions, such as withdrawing from Taiwan."

China and Taiwan are critical to Japan's supply chain and are also key markets for Japanese companies' products and services. According to the survey, 54 percent of firms said heightened tensions between the two had a significant or moderate impact on their business.

In a multiple-choice questionnaire on firms' top concerns, 53 percent cited a halt in sea and air shipments, while 48 percent pointed to instability in the semiconductor supply chain.

When asked about a potential invasion, 22 percent said it was likely or very likely, while only 3 percent said it was unlikely. The majority, 46 percent, said they were unsure.

When asked whether Japan should step up diplomatic efforts to ease tensions between China and Taiwan and prevent an invasion, 35 percent responded affirmatively, 7 percent said Japan had already done enough and 20 percent said they did not know.