In today’s Bulldog wrapup of technology news:

  • Uber defends its safety record after Kalamazoo shootings
  • Verizon is making a big fiber network buy
  • Will United Technologies and Honeywell merge?
  • No lithium battery shipments by air
  • Yahoo’s board moves ahead on analysis of company’s options

The details:

  • Uber’s defense after Kalamazoo shootings

Uber is once again facing tough questions about safety after one of its drivers was charged with murder.

The fast-growing, San Francisco-based ride-hailing company defended its screening of drivers Monday, saying it couldn’t have predicted that driver Jason Dalton would engage in the random shootings that left a half-dozen people dead in Kalamazoo Saturday night. Uber said its safety procedures are robust and don’t need to change.

But some experts say the company needs to take a harder look at potential drivers if it wants to convince riders the service is safe, even as they agreed that Dalton wouldn’t have raised red flags because he didn’t have a criminal record.

Dalton, who had been driving for Uber for less than a month, was charged Monday with killing six people. The shootings began Saturday evening and took place over nearly five hours. The Kalamazoo County prosecutor says Dalton picked up Uber passengers after the first shootings and probably after subsequent shootings.

Uber security chief Joe Sullivan said Dalton cleared a background check and was approved to be a driver on Jan. 25. He had given slightly more than 100 rides and had a rating of 4.73 stars out of a possible five.

Until Saturday, Sullivan said, Uber had no reason to believe anything was amiss.

“No background check would have flagged and anticipated this situation.”

Still, the incident raised more questions about Uber’s security. The company earlier this month agreed to pay $28.5 million to settle two lawsuits that alleged it misled customers about safety procedures and fees. It’s also facing a separate a lawsuit by district attorneys in San Francisco and Los Angeles, who alleged that Uber’s checks failed to prevent the company from hiring several felons.

  • Verizon to buy fiber-optic business for about $1.8 billion

Verizon says it will pay $1.8 billion to buy the fiber-optic network business of XO Communications, in a deal that the wireless phone company said would boost the networks of its customers.

The deal is expected to close in the first half of next year.

New York-based Verizon Communications Inc. says it will also rent XO’s wireless spectrum and has the option to buy the spectrum at the end of 2018.

XO Communications, based in Herndon, Virginia, owns and operators networks that its customers use for Internet access, cloud computing and other uses. Billionaire investor Carl Icahn is chairman and sole shareholder of the company.

  • United Technologies rules out Honeywell deal

United Technologies Corp. has confirmed it talked with Honeywell International Inc. about the possibility of combining the two industrial conglomerates but determined that regulatory obstacles were too high to make a deal feasible.

Shares in United Tech jumped almost 5 percent Monday after news reports citing anonymous sources said the two companies had held merger talks. Honeywell declined comment on the reports.

But late Monday, United Tech acknowledged that “preliminary, exploratory conversations” had been held. It said, however, it did not pursue the talks further because it anticipated significant regulatory obstacles, customer concerns and price issues.

In particular, it said that combining two of the world’s largest players in the aerospace and commercial building industries would face “insurmountable” opposition from government regulators.

  • UN panel bans rechargeable lithium battery shipments

A U.N. panel on Monday approved a temporary ban on cargo shipments of rechargeable lithium batteries on passenger planes because they can create intense fires capable of destroying an aircraft.

The decision by the Montreal-based International Civil Aviation Organization’s top-level governing council isn’t binding, but most countries follow the agency’s standards. The ban is effective on April 1.

“This interim prohibition will continue to be in force as separate work continues through ICAO on a new lithium battery packaging performance standard, currently expected by 2018,” said Olumuyiwa Benard Aliu, the ICAO council’s president.

Namrata Kolachalam, a U.S. Transportation Department spokeswoman, called the ban “a necessary action to protect passengers, crews, and aircraft from the current risk to aviation safety.”

Lithium-ion batteries are used in a vast array of products from cellphones and laptops to some electric cars. About 5.4 billion lithium-ion cells were manufactured worldwide in 2014. A battery is made up of two or more cells. A majority of batteries are transported on cargo ships, but about 30 percent are shipped by air.

Airlines flying to and from the U.S. that accept lithium battery shipments carry 26 million passengers a year, the Federal Aviation Administration estimates. The ban doesn’t apply to batteries packaged inside equipment like a laptop with a battery inside.

  • Yahoo’s board hires investment banking firms to review options

Yahoo’s board has hired three investment banking firms to evaluate potential bids for its Internet operations in the clearest sign yet that CEO Marissa Mayer may not have much more time to turn around the struggling company.

The move announced Friday comes 2 1/2 weeks after Yahoo disclosed it would consider “strategic alternatives” while Mayer cuts costs through mass layoffs, office closures and a purge of unprofitable products.

Mayer believes the overhaul will boost profits and sharpen Yahoo’s focus on mobile apps and other services most likely to revive the company’s revenue growth after years of decline.

Some Yahoo shareholders frustrated with a steep drop in the company’s stock price have been pushing for a sale of the Internet operations instead.

The board has now responded to that pressure by hiring investment bankers Goldman Sachs, J.P. Morgan and PJT Partners to set up a process for meeting with companies interested in buying all or parts of Yahoo’s business. A special committee of Yahoo’s directors will discuss the options with the bankers and the company’s legal advisers, Cravath, Swaine & Moore.

While the board mulls those alternatives, Mayer will continue to pursue a turnaround plan that includes jettisoning 15 percent of Yahoo’s workforce.

“We believe that pursuing these complementary paths is in the best interests of our shareholders and will maximize value,” Yahoo Chairman Maynard Webb said in a statement.