BEIJING (Reuters) - More than 420 Beijing-based companies have opened offices in neighboring Tianjin this year, pledging to invest 160 billion yuan ($23.14 billion), state news agency Xinhua reported on Friday.

The Chinese government has been campaigning for an integrated megacity of Beijing, Tianjin and Hebei province since 2014, in an effort to ease pressure on its crowded capital by transferring industries further out into Tianjin and Hebei.

It dubbed the area "Jing-Jin-Ji", using shortened versions of the names of the cities and province.

Firms that have pledged to put down over 1 billion yuan in Tianjin include China's home-grown ride-hailing application Didi Chuxing and financial service platform Gome Finance, Xinhua said, citing the Tianjin Economic and Technological Development Zone Management Committee.

It's not immediately clear how much investment has been made by those firms in Tianjin this year.

(Reporting by Yawen Chen and Nicholas Heath; Editing by Gopakumar Warrier)