Brazilian Finance Minister Fernando Haddad and his Argentine counterpart, Sergio Massa, said the proposal still needs to be endorsed by a CAF board meeting scheduled for Sept. 14.

"We have no doubt that they will approve the operation because it was the CAF's initiative," Massa told the press after a meeting with Haddad in Brasilia.

The offer represents a sweeter deal for cash-strapped Argentina compared with the one initially proposed by Brazil, which involved the provision of around $140 million in guarantees by the Argentine government in Chinese yuan for Brazilian exports of equal value.

The initiative will involve state-run lender Banco do Brasil BBAS3.SA as Brazilian exports guarantor, Haddad said.

Argentina, Brazil's third-largest trading partner, is suffering an economic crisis marked by soaring inflation and dwindling central bank reserves.

Yuan guarantees initially proposed by the Brazilian government would provide security to its companies concerning their sales receipts amid Argentina's dollar shortage.

Haddad acknowledged, however, that with this initial arrangement, Argentina's yuan reserves would decrease.

"Argentina, with the support of CAF, does not need to give up these reserves to secure exports," he said, stressing that Brazil's initial proposal would stand and it would proceed "with what brings more comfort to Argentina and does not pose any kind of issue for us."

According to Haddad, the CAF's offer of counter-guarantees involves primarily automotive trade, but food products as well.

(Reporting by Victor Borges and Marcela Ayres; Editing by Chris Reese and Leslie Adler)