(Reuters) -Portillo’s Inc, a restaurant chain known for its Chicago-style hot dogs, on Monday made public its filing for a U.S. stock market listing, revealing a nearly 19% jump in revenue for the two quarters ended June 27. Restaurant chains have seen sales rebound strongly over the last few months as the rollout of vaccines and lifting of COVID-19 restrictions gave people more confidence to start dining out again after a year of ordering in. Portillo"s revenue for the two quarters stood at of $258 million, compared with $217.3 million a year earlier, according to the filing here. It recorded a net income of $13.9 million in the same period versus a loss of $733,000, Portillo"s said. Sales last year were hit by the COVID-19 pandemic, the Oak Brook, Illinois-based company said, with the most significant decline in sales coming in late March through April 2020. The first Portillo’s hot dog stand, “The Dog House”, came up at Villa Park, Illinois in 1963 after founder Dick Portillo invested $1,100 into a trailer that had no running water. Four years later, it was renamed “Portillo’s”. The company, backed by private equity firm Berkshire Partners, had confidentially filed here for its initial public offering in July. Jefferies, Morgan Stanley, BofA Securities and Piper Sandler are among the underwriters for the offering. Portillo’s will list on Nasdaq under the symbol “PTLO”.