(Adds background, banks managing the offering)
SAO PAULO, July 29 (Reuters) - Brazilian online lender Banco Inter SA raised 1.3 billion reais ($343.80 million) in a share offering that lured Japan's Softbank Group Corp as an investor, a source with knowledge of the matter said on Monday.
The bank priced its units, comprised of one common share and two preferred shares each, at 39.99 reais, the source added, without disclosing the number of shares acquired by Softbank.
Earlier this month, the bank said it would raise roughly 1 billion reais to expand its loan book, invest in technology and acquire companies.
Investment banking units of Banco Bradesco SA, Goldman Sachs & Co, Banco BTG Pactual SA, JPMorgan Chase & Co, Banco Santander Brasil SA and state-owned Caixa Economica Federal managed the offering.
The share offering comes 15 months after Banco Inter went public on the Sao Paulo stock exchange. Since then, it has grown at a breakneck pace, with the number of clients surging to 2.5 million from roughly 500,000 in March 2018.
Brazilian financial start-ups, such as Banco Inter and Nubank, have lured clients by offering fee-free bank accounts, challenging traditional banks.
Banco Inter is controlled by Brazil's Menin family, which also controls homebuilder MRV Engenharia e Participações SA .
Brazilian financial blog Brazil Journal reported earlier that Banco Inter had lured Softbank, buying almost 1 billion in units.
Earlier this month, Softbank led a $231 million new financing round for Brazilian lending platform Creditas.
$1 = 3.7813 reais Reporting by Carolina Mandl; Editing by Sandra Maler and Leslie Adler