Overseas acquisitions by Chinese companies plummeted in the first half of 2019, as tighter capital controls at home and growing wariness of Chinese takeovers abroad stifled such activity.Chinese businesses spent $24.5 billion on foreign acquisitions during those six months, down 42% on the year and less than one-fifth of the most recent peak seen in the first half of 2016, data from Dealogic shows. No deals exceeded $10 billion, the kind that attracts the attention of regulators.