Feb 19 (Reuters) - The Chinese government threatened to retaliate against leading Czech companies if a senior Czech official made good on a planned visit to Taiwan, according to a diplomatic message reviewed by Reuters.

The Jan. 10 letter, sent by China’s embassy in Prague to the Czech president’s office, suggested that automaker Skoda, lender Home Credit Group, and musical instrument maker Petrof Pianos would suffer if late Czech lawmaker Jaroslav Kubera visited the self-ruled island as planned.

Chinese officials in Beijing did not immediately return a message seeking comment. Taiwan’s foreign ministry said it would issue a statement later in the day.

The chairman of the Czech Republic’s upper house of parliament, Kubera was the second-most senior official in the country after President Milos Zeman. His planned visit to Taiwan - which Beijing considers a breakaway province - had already raised concerns that China would retaliate against the Central European country’s business community.

The debate was made moot when Kubera died unexpectedly on Jan. 20, ahead of the planned trip, but the letter reveals how explicit Beijing had been about who would suffer if the visit went forward.

The message - written in Czech - noted that Kubera’s trip would be seen as a “serious breach” of the so-called one China policy, under which Beijing insists it is the sole representative of China.

The letter said that “China is the largest foreign market for many Czech companies like Skoda Auto, Home Credit Group, Klaviry Petrof and others.”

“Czech companies whose representatives visit Taiwan with Chairman Kubera will not be welcome in China or with the Chinese people,” the letter continued. “Czech companies who have economic interests in China will have to pay for the visit to Taiwan by Chairman Kubera.”

The Czech government has said in the past that it does adhere to the one-China policy. (Reporting by Raphael Satter and Nick Carey; Additional reporting by Robert Muller and Jan Lopatka; Editing by Raju Gopalakrishnan)