WASHINGTON—The U.S. and China signed a trade deal that officials say will lead to a sharp increase in sales of U.S. goods and services to China, further open Chinese markets to foreign firms—especially in financial services—and provide strong new protections for trade secrets and intellectual property.

The eight-part agreement acts as a cease-fire in a two-year trade war that has roiled markets world-wide and cut into global growth. But it leaves in place U.S. tariffs on about $370 billion in Chinese goods, or about three-quarters...