SYDNEY, July 16 (Reuters) - China's Ping An Insurance said on Tuesday it has raised $3.5 billion through a convertible bond sale.

The five-year bond's coupon was set at 0.875% per annum, paid semi-annually, Ping An said in a regulatory filing.

Its conversion price was set at HK$43.71 per share, the statement showed.

Ping An's Hong Kong-listed stock was down 3.88% at HK$34.65, while the broader Hang Seng Index was down 1.26%.

The company's Shanghai-listed stock is off nearly 3%.

The sale was multiple times oversubscribed with about 100 investors placing orders, said a person familiar with the deal.

The 20 biggest investors bought over 70% of the deal, the person said, declining to be identified discussing non-public information.

The bond was classified as Reg-S meaning it was aimed at buyers outside of the U.S.

It is the largest-ever Reg-S-only convertible bond, the largest convertible bond in the insurance sector, and the first offshore convertible bond by a Chinese insurer, the person said.

Morgan Stanley and JPMorgan led the transaction, the filing showed. (Reporting by Scott Murdoch; Editing by Jacqueline Wong and Christopher Cushing)