SYDNEY - Airport Authority Hong Kong raised $7 billion this week by issuing bonds in three currencies - the largest ever public offering of bonds by a Hong Kong company.

Most of that was done in a three-tranche dollar bond deal which garnered $4.15 billion, according to a term sheet seen by Reuters on Thursday.

It raised $1.3 billion in a 3.5-year bond, $1.85 billion in a 5.5-year deal and $1 billion in a 10-year tranche.

The firm also raised the equivalent of $2.8 billion in Hong Kong dollar and Chinese yuan bonds this week, term sheets for those deals showed. The Hong Kong dollar deal of HK$18.5 billion ($2.4 billion) was also the largest ever from a company in that currency.

The dollar tranche was the biggest for a Hong Kong company since 2003, book runners said.

The company plans to use some of the proceeds to fund ongoing work for its third runway system which was opened in November after nine years of construction, according to the dollar bond prospectus. Aviation Authority Hong Kong is also planning a staged expansion of the airport's terminal 2 facility.

Some of the money raised will also pay down debt due to mature this year, the prospectus said.

Investors lodged $3.4 billion worth of a bids for the shortest dated dollar bond, $5.8 billion for the 5.5-year deal and $8.5 billion for the 10-year bond, they said.

Airport Authority Hong Kong did not immediately respond to an emailed request for comment from Reuters.

More than $10 billion has been raised in dollars in Asia this week, according to LSEG data and term sheets seen by Reuters.

Dealmakers expect about a 20% rise in dollar issuance across the region in 2025, as lower U.S. interest rates since late last year make dollar bonds more attractive to issuers.

(Reporting by Scott Murdoch; Editing by Kim Coghill and Edwina Gibbs)