WASHINGTON, July 7 (Reuters) - The U.S. House Oversight Committee has asked the chief executives of three gunmakers to testify on July 20 as part of its investigation into the firearms industry following a wave of high-profile mass shootings, the panel said on Thursday.

The panel called on the CEOs of Smith & Wesson Brands , Sturm, Ruger & Co, as well as privately held Daniel Defense to appear, according to letters sent to the companies released by the panel.

"I am deeply troubled that gun manufacturers continue to profit from the sale of weapons of war, including AR-15-style assault rifles," committee chairwoman Representative Carolyn Maloney, a New York Democrat, wrote.

"Products sold by your company have been used for decades to carry out homicides and even mass murders, yet your company has continued to market assault weapons to civilians."

Representatives for the gunmakers did not immediately respond to requests for comment. Lawmakers gave the CEOs until Friday to respond to the committee.

The panel cited Monday's mass shooting at a Fourth of July parade in Highland Park, Illinois, where a gunman allegedly killed at least seven people and wounded dozens of others with a high-powered rifle.

OVER 200 MASS SHOOTINGS THIS YEAR

Last month, the panel heard from victims and relatives of recent mass shootings at an elementary school in Uvalde, Texas, and a grocery store in Buffalo, New York.

Lawmakers are grappling with a recent spate of deadly attacks across the United States, which has seen more than 200 mass shootings just this year.

A modest bipartisan package of gun reforms was signed into law in late June while the U.S. Supreme Court separately expanded gun owners' rights. Some U.S. states have separately moved to act on guns following the top court's ruling.

The July 20 hearing will look into gun sales and marketing "and the broad civil immunity that has been granted to manufacturers," wrote Maloney.

"Your testimony is crucial to understand why your company continues to sell and market these weapons to civilians, what steps your company plans to take to protect the public, and what additional reforms are needed to prevent further deaths from your products," Maloney wrote in the letters to the CEOs of gunmakers. (Reporting by David Shepardson and Susan Heavey in Washington; additional reporting by Uday Sampath in Bengaluru; Editing by Emelia Sithole-Matarise and Bernadette Baum)