Hong Kong maintained its position as the biggest overseas investor on the Chinese mainland in the first seven months of the year, according to the latest statistics from the Ministry of Commerce.

In the Jan.-July period, Hong Kong invested 12.3 billion U.S. dollars on the mainland, up 20 percent from a year earlier, involving 8,782 projects.

Hong Kong had invested an accumulative 292.1 billion U.S. dollars on the mainland by the end of July, taking a 40-percent share in the total investment the mainland had received from overseas since 1978.

The mainland's exports to Hong Kong in the first seven months surged 23.9 percent to 99 billion U.S. dollars, while imports rose 14.2 percent to 6.8 billion U.S. dollars.

Meanwhile, the mainland saw the number of its Macao-invested projects increase 16 percent to 514, with investment value rising 15.9 percent to four million U.S. dollars.

The mainland's exports to Macao rose 23 percent to 1.47 billion U.S. dollars, while imports were down by 7.4 percent to 150 million U.S. dollars.