BEIJING, CHINA — Ford Motor has chosen China for its largest factory expansion program in a half century, announcing on Thursday that it would build a $760 million assembly plant in Hangzhou, two weeks after announcing another $600 million plan to expand an assembly plant in Chongqing and less than six weeks after completing a third assembly plant in Chongqing.

Ford is late to China’s party, and its new factories will open in a slowing, increasingly competitive Chinese market. Rapid factory construction in China is a throwback to the company’s last big factory building campaign in the 1950s, when models like the Thunderbird captured the hearts and wallets of young Americans and when Ford was racing to increase capacity in postwar Europe, Australia and South Africa.

Auto sales in China rose just 2.5 percent last year, after a decade of double-digit annual growth. Sales were down 1.3 percent in the first quarter of this year from a year earlier, the first quarter to show a decline in seven years, according to official figures.

Ford’s ambitious investment plans in China, where it holds a little over 2 percent of the market, represent “a sharp contrast to the old Ford in China, which was tentative, thin on products and short on money for investment,” said Michael Dunne, a longtime auto consultant in China.