BRASILIA, Feb 5 (Reuters) - Brazilian drug maker União Química expects to have regulatory approval and a government contract by next week for Russia's Sputnik V vaccine against COVID-19, its director for international business Rogerio Rosso told Reuters on Friday.

Rosso said the company expects to draw up a contract by Wednesday with the health ministry for an initial 10 million ready-for-use imported doses based on a reference price of $10 per dose.

He said the ministry is also interested in buying the firm's entire domestic production of Sputnik V, an estimated 8 million doses a month from April, for Brazil's national immunization program.

Rosso added he expects Brazilian health regulator Anvisa will approve emergency use of the Russian vaccine next week, as the agency eased requirements for such an authorization.

The first of 10 million doses committed by Russia are ready for dispatch to Brazil as soon as Anvisa greenlights the shot.

Anvisa said in a statement that it discussed with company representatives the emergency use approval based on late stage trials conducted outside Brazil. The Health Ministry did not reply to a request for comment.

With approval by Lebanon on Friday, Sputnik V has been authorized for emergency use in 18 countries besides Russia, said the Russian Direct Investment Fund (RDIF), which is marketing the vaccine. The two-dose vaccine has an efficacy of 91.6%, according to data published on Tuesday in The Lancet medical journal.

RDIF chief executive Kirill Dmitriev has said Brazil could become a Sputnik V supplier to its neighbors in Latin America, where six nations have approved the vaccine, including Argentina, which started immunizations with it in December.

Rosso, a former congressman and governor of Brasilia, said that would have to wait if the Brazilian government buys União Química's output, at least until the company can ramp up production later this year with additional equipment. (Reporting by Anthony Boadle Editing by Brad Haynes, Aurora Ellis and Sonya Hepinstall)