Today: An investigation into fires in Tesla’s Model S reaches its conclusion with a promise of a fix, and the electric car company compromises on its sales structure in deal with New York. Also: Two more Silicon Valley IPOs close out first quarter.

The Lead: Tesla offers fix for Model S fires, reaches deal with New York

Two challenging issues for Tesla Motors seemed to reach their conclusion Friday, and Wall Street voiced its approval by pushing the company’s stock back up at the end of a rough week.

A federal investigation — sparked by fires caused by road debris striking the underside of the Palo Alto company’s Model S — reached its conclusion Friday with Tesla announcing that it would place stronger shields on the belly of its signature offering. The cars are not being recalled for the addition of the plates, but Model S units manufactured since March 6 will include the safety feature and current Model S owners can request the free retrofit.

“The underbody shields are not needed for a high level of safety,” founder and CEO Elon Musk said in a Friday blog post. “However, there is significant value to minimizing owner inconvenience in the event of an impact and addressing any lingering public misperception about electric vehicle safety.”

Kelley Blue Book analyst Karl Brauer told the Mercury News that the outcome was good for Tesla, explaining, “It could have been a much more expensive fix if NHTSA decided they needed to redesign the battery pack,” but added that it was basically a recall that didn’t use the word “recall.”

“NHTSA’s reaction to the problem and how they are resolving it is basically a recall,” Brauer said Friday. “They are closing the investigation only because Tesla is making this change to cars they are producing and sending out notices, suggesting people come in and get the change to cars already made.”

Friday afternoon, Tesla received more good news when negotiations with New York about the company’s direct-sales structure led to a compromise that will allow Tesla to maintain its current sales outlets in the state and possibly add more. Similar to a deal struck earlier this week in Ohio, the breakthrough could lead to other compromises as auto dealers fight the company’s entry into markets in several states, and Tesla seeks to avoid results like New Jersey’s ban on sales.

Lou Roberti, chairman of New York’s Automobile Dealers Association, Tesla’s combatant in the state, told the Wall Street Journal that Friday’s compromise could “serve as a model for other states as they consider how to accommodate Tesla and a distribution system that has served the public well.”

Diarmuid O’Connell, Tesla’s vice president of business development, told the Journal that the agreement “protects franchise dealers’ existing business while allowing Tesla to continue to pursue its mission of catalyzing the market for sustainable transportation.”

Tesla stock rebounded from recent weakness after the investigation officially ended Friday morning, gaining 2.4 percent to $212.37, and shares moved closer to $213 in late action following reports of the New York compromise. the company’s high-flying stock had been scuffling before Friday, dropping 9.4 percent for the week and 21.8 percent form the all-time intraday high of $265, set in late February.

The next big milestone for Tesla will be a decision on the placement of its planned battery-production facility, dubbed the Gigafactory. A report Friday suggested that Reno is in the lead for the Gigafactory, as it has had more advanced discussions than other possible locations.

SV150 market report: Two Silicon Valley IPOs close out busy quarter

Tech stocks bounced back slightly from a weak week Friday, as two more Silicon Valley companies made their debuts on Wall Street.

Sunnyvale’s Aerohive Networks brought in $75 million in an initial public offering before making its debut Friday morning on the New York Stock Exchange, where shares initially dipped from the $10 IPO price before closing at $9.99. The company, which offers a wireless network option for large businesses that utilizes cloud management tools and focuses on mobile-device usage, is studded with executives and engineers that helped NetScreen Technologies perform a huge IPO in 2002 before being acquired by Juniper Networks in a $4 billion deal in 2004. Pleasanton’s Energous, a young company seeking to make equipment that will charge mobile devices from a distance with no wires, also went public and enjoyed a much larger first-day pop, rising 76.3 percent from an IPO price of $8 to a closing price of $11.45.

The debuts ended a first quarter that also included Thursday’s debut of San Leandro’s TriNet Group and earlier debuts from San Jose’s A10 Networks, San Francisco’s Castlight Health, Mountain View’s Coupons.com and a host of biotechnology companies including Redwood City’s Versartis. Nasdaq reported Thursday that it had hosted 45 IPOs in the first quarter, its busiest start to the year since 2007, including all 22 biotech companies that have debuted this year. The total amount raised for Nasdaq IPOs was $2.6 billion, which paled in comparison to the total for the NYSE, which had 30 IPOs that raised $8.75 billion, 72 percent of all the proceeds raised in U.S. IPOs in the first quarter, according to spokeswoman Judy Shaw. The pace picked up at the end of the first quarter and should continue to be strong, with Silicon Valley companies Corium International and Five9 expected to go public next week, along with tech companies from elsewhere such as GrubHub, OPower and The Rubicon Project.

Apple dropped 0.1 percent to $536.86 amid reports that it will expand its sapphire production in Arizona, and Google gained 0.5 percent to $1,120.15 while throwing marketers a bone in its Gmail setup. Facebook dropped 1.6 percent to $60.01 after Thursday afternoon’s focus on using drones and lasers to expand Internet access, and rival Twitter gained 2.1 percent to $47.30 while reportedly gearing up to offer a mobile advertising product to app makers. Gilead Sciences fell 4 percent to a four-month low of $68.55 after a report said that new prescriptions for its Sovaldi hepatitis C drug declined as Congress investigates the pricing of the breakthrough drug.

Up: Sandisk, Symantec, Applied Materials, Tesla, Twitter, Cisco, Intel, Juniper, LinkedIn, SolarCity, Yahoo, Oracle, Nvidia, Adobe, Google

Down: Gilead, Yelp, Palo Alto Networks, Facebook, Netflix, Zynga, Pandora, AMD, Salesforce, VMware, SunPower, NetApp, Workday, Apple

The SV150 index of Silicon Valley’s largest tech companies: Up 0.52, or 0.03 percent, to 1,510.38

The tech-heavy Nasdaq composite index: Up 4.53, or 0.11 percent, to 4,155.76

The blue chip Dow Jones industrial average: Up 58.83, or 0.36 percent, to 16,323.06

And the widely watched Standard & Poor’s 500 index: Up 8.58, or 0.46 percent, to 1,857.62

Check in weekday afternoons for the 60-Second Business Break, a summary of news from Mercury News staff writers, The Associated Press, Bloomberg News and other wire services. Contact Jeremy C. Owens at 408-920-5876; follow him at Twitter.com/jowens510.