By Jeffrey T. Lewis

SAO PAULO--Bankruptcy filings by Brazilian companies jumped in June from May as the closing of non-essential activities during the coronavirus pandemic slammed small businesses.

Filings increased 28.9% from May, and soared 87.1% from June 2019, credit rating bureau Boa Vista SCPC said Tuesday. Small businesses were by far the worst hit by social distancing measures, representing 93.4% of the total filings in the month, according to Boa Vista.

Medium-sized businesses filed 5.3% of the bankruptcy requests last month, and big companies filed the remaining 1.3%, the credit rating bureau said. Big companies have been better able to handle the downturn, with easier access to credit or with enough cash on hand to pay their bills.

Brazil's government has offered businesses various forms of credit to help them keep workers on the books, but many of the smallest companies have had difficulty accessing the money. Income-starved businesses should start getting some relief in coming months as states and towns permit many to reopen.

In Sao Paulo, Brazil's most populous city, businesses including restaurants, bars, shops, gyms and hair dressers have been allowed to resume activity as the pace of new infections and deaths and hospital occupancy rates have stabilized.

Write to Jeffrey T. Lewis at jeffrey.lewis@wsj.com