A $20 billion non-recourse loan that forms part of the financing backing China National Chemical Corp's SFr43bn ($43.45 billion) acquisition of Swiss seeds and pesticides company Syngenta launched into syndication on Thursday, banking sources said.

The financing has been underwritten by HSBC, Credit Suisse, Rabobank and UniCredit, the sources said.

The financing is split between a US$15 billion bidco tranche to part finance the acquisition and a US$5 billion tranche to backstop Syngenta's existing debt that is subject to change of control clauses.

The loans carry a mixture of maturities, one of the sources said, but are mostly short-term bridge loans.

The financing has been launched to a tight group of existing lenders to Syngenta and ChemChina. Lenders are being asked to commit US$1.25 billion each to the financing.

A bank meeting will be held in the middle of next week, and commitments are expected by the end of March or early April.

The loan, which is being raised at the Syngenta level, forms part of a wider US$50bn financing that also includes US$30 billion of recourse loans at the ChemChina level that have been underwritten by China Citic Bank International.