TAIPEI, Oct 5 (Reuters) - Sales at Hon Hai Precision Industry, known by its trade name Foxconn and as a key supplier of Apple Inc's products, rose by 0.5% rise in September.

The world's largest contract electronics manufacturer reported revenues of T$587.79 billion ($19 billion) in September, up from T$584.93 billion from a year earlier, it said in a filing to the Taiwan stock exchange.

Although only a slight yearly increase, the monthly revenue figure was the company's highest for September.

Taipei-based Foxconn, which manufactures the bulk of Apple's iPhones in China for sale in the United States, faces challenging quarters ahead as Washington plans to impose additional tariffs on Chinese imports, including smartphones.

The sales update came after Apple launched its three new iPhone models in September and cut the starting price.

In the second quarter, Foxconn posted a 2.5% profit drop, a slightly smaller fall than analysts expected.

Foxconn is already battling weak global demand for other electronics devices, which has forced it to consider selling its $8.8 billion display panel factory in China, Reuters reported in August. ($1 = 30.9480 Taiwan dollars) (Reporting by Yimou Lee; Editing by Alexander Smith)