BEIJING, Jan 19 (Reuters) - Overall net profits of China"s central government-owned state firms rose 29.8% year-on-year to 1.8 trillion yuan ($283.56 billion) in 2021, according to a statement from the state assets regulator on Wednesday, higher than a 2.1% growth in 2020. The overall revenue of central government-owned state firms grew 19.5% from a year earlier to 36.3 trillion yuan in 2021, the State-owned Assets Supervision and Administration Commission also said. ($1 = 6.3479 Chinese yuan renminbi)