UPDATE 1-BlackRock to offer gun-free investment strategies, ETFs

(Adds details on potential company impact, client views and index make-up, byline)

BOSTON, April 5 (Reuters) - Asset manager BlackRock Inc said on Thursday it will offer new investment strategies and ETFs that exclude civilian firearms producers and retailers, following through on plans it outlined last month to study such products in the wake of a high school massacre in Florida.

According to a client update sent by a company spokesman, BlackRock will offer a new line of firearm-free products to big institutional investors and pension plans that track broad market indexes like the S&P 500 and Russell 1000.

The world's largest asset manager also said it would create two new exchange-traded funds that would exclude gun makers and retailers, and add similar screens to existing stock and bond ETFs that already screen stocks for social, environmental and governance factors.

Strong investor interest in the products in theory could weaken demand for shares of gun makers such as American Outdoor Brands Corp and Sturm Ruger & Co, where BlackRock funds have large stakes, although it could take awhile for clients to move enough money to make an impact.

BlackRock has about $6 trillion under management. The firm and rivals have struggled in recent years to find ways to balance various social and environmental issues important to their clients with their need to own stocks that are represented in big worldwide indexes.

BlackRock acknowledged in the client note that it runs money for a diverse set of clients "who have a wide range of views on firearms" and that the new funds are a response to client interest.

The ETFs getting the new screens have had little exposure to firearms makers in any case, BlackRock said.

Specifically, BlackRock will offer five new strategies to track broad indexes, including the S&P 500, the Russell 1000, Russell 2000 and Russell 3000, and the MSCI World ex-US index.

(Reporting by Ross Kerber; Editing by Dan Grebler)