The shake-up consolidates Stringer's control of the sprawling conglomerate and may make it easier to unite factions that analysts say have hindered its ability to develop hit products.
Shares of Sony fell 0.48 percent to 1,660 yen, but outperforming the Nikkei 225 Average, which was down 3.8 percent.
Nikko Citigroup raised its rating on Sony to "buy/high risk" from "hold/high risk", citing expectations for accelerated restructuring after the management shake-up, and it raised its target price for Sony shares to 2,200 yen from 2,100 yen.
But other analysts including Credit Suisse's Koya Tabata were not convinced that the shift would automatically be a solution to Sony's problems such as growing inventory, a high cost structure and fragmented operations.
"We remain unsure about whether consolidating control into the hands of Chairman Howard Stringer will change the business model significantly and fundamentally strengthen Sony's operations," Tabata wrote in a note to investors.
He kept his rating on Sony at "underperform" with a target price of 1,000 yen.
Welsh-born American Stringer will be the first foreigner to head Sony .
The problems in electronics, including losses in TV operations, are a main reason Sony is tumbling into its first annual net loss in 14 years.
Stringer, 67, on Friday introduced a team of four younger executives, three of them in their 40s—including Kazuo Hirai, 48, head of Sony's game unit—to spearhead efforts to bring together Sony's sprawling empire, spanning TVs, games, movies and semiconductors, to develop products and services for the digital age.
At a news conference at Sony's Tokyo headquarters, Stringer acknowledged Sony had not been quick enough, and had lost to American rivals like Apple as well as Asian ones like Samsung Electronics.
And Sony had to do more to integrate its hardware gadget strengths with software businesses like Internet services, video gaming and movies and other entertainment content, he said.
"We must drive change along several fronts," Stringer told reporters. "We must regroup and rationalize our important core electronics product business. We must accelerate the introduction of innovative network product and service offerings."