Powerhouse investment firm BlackRock is turning up the pressure on gun makers.

The company, which manages trillions for other investors, said Friday that the shooting in Parkland, Florida, has caused it to reexamine its holdings in both gun makers and gun retailers.

BlackRock (BLK) is the largest shareholder in gun makers Sturm Ruger and American Outdoor Brand, the owner of Smith & Wesson, and the second-largest shareholder in Vista Outdoor (VSTO).

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In a statement Friday, BlackRock said it will start offering clients the option to invest in funds that exclude firearm manufacturers and retailers. It also said it will more actively engage with gun manufacturers, and in some instances vote against the wishes of company management.

"For manufacturers and retailers of civilian firearms, we believe that responsible policies and practices are critical to their long-term prospects. Now more so than ever," said BlackRock.

It said it has already had "constructive discussions" with some of the companies. It plans to ask gun makers how they'll deal with the reputation and legal risks associated with manufacturing civilian firearms, and if they monitor whether their products are used in crimes.

BlackRock will ask retailers what proportion of their sales firearms and ammunition represent, and what steps they have taken to prevent the misuse of firearms that they sell.

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"This is an issue of tremendous urgency and we are bringing, and will continue to bring, a sense of urgency to our engagement efforts in this area," BlackRock said.

Spokespeople for the gun makers either did not respond to a request for comment or could not be reached on Friday.

Shares of the gun makers have been down between 5% and 20% since the Parkland, Florida shooting, although Sturm Rurger (RGR) and American Outdoor Brands (AOBC) were higher Friday.

-- CNN's Danielle Wiener-Bronner contributed to this report.