Adds more details from terms sheet throughout

SINGAPORE, May 14 (Reuters) - Chinese pharmaceutical services company WuXi AppTec Co Ltd 603259.SS has launched a 6.78 billion yuan ($1 billion) zero-coupon convertible bond offering due in 2027, according to a term sheet seen by Reuters on Thursday.

The bonds mature in May 2027. Investors can convert them into WuXi AppTec's Hong Kong-listed shares 2359.HK. The bonds are denominated in yuan, linked to offshore yuan and settled in U.S. dollars, the sheet shows.

WuXi AppTec will use the proceeds for global expansion and general corporate purposes, according to the sheet.

The company is offering the bonds at 103.0% to 103.5% of face value. That gives a yield to maturity of minus 3.5% to minus 3.0% a year.

The conversion price will be set at a 20% premium to the reference Hong Kong share price. Pricing is expected on or around May 14, according to the sheet.

WuXi AppTec did not immediately respond to an email seeking comment on Thursday.

($1 = 6.7851 Chinese yuan renminbi)