FRANKFURT, Sept 8 (Reuters) - German defence supplier Hensoldt has filed for a Frankfurt stock market listing later this month, as the private equity-owned company seeks to raise funds for growth and to strengthen its balance sheet.

The deal is expected to value the former Airbus unit, which buyout group KKR bought in 2016, at 2.5-3 billion euros ($3-3.5 billion), including debt, people close to the matter said.

New and existing shares worth 20-30% of the company are expected to be listed on the stock exchange, the people said, while the company declined to comment on the size and valuation of the listing. ($1 = 0.8463 euros) (Reporting by Arno Schuetze Editing by Michelle Adair)