The daily business briefing: April 19, 2018

Texas-based Slide Fire, the largest maker of bump stock devices, has posted a notice on its website saying it is shutting down. The company said it would stop taking orders at midnight on May 20. Bump stocks can be fitted onto semi-automatic rifles to make them fire continuously, like fully-automatic machine guns. Stephen Paddock had several weapons equipped with the devices when he fired onto a crowd at a concert from a 32nd-floor hotel room in Las Vegas on Oct. 1, killing 58 people. Gun-control activists and President Trump have called for a nationwide ban on bump stocks.

The Federal Aviation Administration said Wednesday that it would call for inspections of about 220 jet engines like the one that exploded on a Southwest Airlines jet this week, destroying a window and killing a passenger who was nearly sucked out of it due to rapid decompression. Investigators said a fan blade in the engine triggered an explosion that sent bits of the engine slamming into the window. The FAA's order requires ultrasonic inspections within six months of engines that are the same model as the one on the Southwest jet if they have made a certain number of takeoffs.

Procter & Gamble has agreed to buy German drug maker Merck KGaA's consumer-health business for $4.2 billion. The deal will give P&G, which makes a host of products including Crest toothpaste and Pampers diapers, Merck's stable of vitamins, decongestants, and over-the-counter health products, which had sales growth of 6 percent over the last two years. Merck offered the unit for sale last year as part of an effort to direct more resources into testing new medicines. Merck had initially set the price for the unit more than 15 percent higher, discouraging initial suitors such as Nestle, Perrigo, and Stada owners Bain and Cinven. Shares of P&G, which reports earnings on Thursday, rose by 1.3 percent overnight.

Amazon CEO Jeff Bezos said the online retail giant has 100 million subscribers worldwide to its Prime service, which offers free two-day shipping on some items, and access to other services, such as a streaming-video library. Bezos' revelation in his annual letter to shareholders marked the first time Amazon has revealed how many people pay for Prime service, which costs $99 a year. "In 2017, Amazon shipped more than 5 billion items with Prime worldwide, and more new members joined Prime than in any previous year — both worldwide and in the U.S.," Bezos wrote in his letter. The news came as Amazon reportedly prepares to start selling a television with built-in Fire TV capabilities at Best Buy stores.

U.S. stock futures were flat early Thursday, sending Wall Street into a second day with no clear direction. Futures for the Dow Jones Industrial Average, the S&P 500, and Nasdaq-100 inched down by less than 0.1 percent. On Wednesday, the Dow fell by less than 0.2 percent, while the S&P 500 gained by less than 0.1 percent and the Nasdaq Composite rose by about 0.2 percent. If U.S. stocks remain stuck roughly where they are they will post a gain for the week, thanks to a lift from strong first-quarter earnings. "With a lack of geopolitical drivers, markets have entered a somewhat quietened period of trading," said Hantec Markets analyst Richard Perry in a note.