BEIJING, May 6 (Xinhua) -- More listed firms on the Shenzhen Stock Exchange expanded their businesses overseas in 2018, according to the bourse.

A total of 1,397 firms out of 2,156 on the bourse which had disclosed their annual financial information had overseas operations in 2018, accounting for 64.8 percent of total Shenzhen-listed firms and up 0.14 percentage points year on year, a report released Sunday showed.

Overseas operation revenue totaled 1.73 trillion yuan (about 255.2 billion U.S. dollars) last year, up 12 percent year on year. A total of 33 firms saw their overseas operation revenue exceed 10 billion yuan last year.

Electronics, home appliances and machinery were major revenue contributors, the report showed.