SAO PAULO, July 20 (Reuters) - Brazilian oncology clinics chain Oncoclinicas, which is backed by Goldman Sachs Group Inc , plans to raise roughly 3.5 billion reais ($671.26 million) in an initial public offering, amid a dealmaking boom in the healthcare sector in the country.

Oncoclinicas set its price per share at between 22.21 reais and 30.29 reais. The company will decide on the final price on Aug. 6.

Both the company and its shareholders plan to sell 135.1 million shares in the IPO, but this volume could increase by 35% depending on investors' demand for it.

Oncoclinicas plans to use the IPO proceeds to grow, including through mergers and acquisitions.

It posted net revenue of 2 billion reais in 2020 and a net loss of 125.2 million reais.

Goldman Sachs has a 93.5% stake in the company, but said it plans to reduce that to roughly 60% after the IPO.

Investment banking units of Goldman Sachs, Itau Unibanco, Citi, UBS BB, Santander, JPMorgan and XP will manage the offering.

($1 = 5.2141 reais) (Reporting by Carolina Mandl Editing by Paul Simao)