News Corp, CBS in spotlight at Sun Valley

* News Corp, CBS under scrutiny as acquisitions disappoint

* Spotlight also on Sony's Howard Stringer to do deals

By Yinka Adegoke and Alexei Oreskovic

NEW YORK/SUN VALLEY, Idaho July 8 (Reuters) - News Corp's (NWSA.O) Rupert Murdoch and CBS Corp's (CBS.N) Leslie Moonves will likely be under a harsh spotlight at this year's gathering of media business chiefs in Sun Valley, Idaho.

The conference, organized by boutique investment bank Allen & Co, is supposed to be a retreat for the biggest names in the business, but not everyone will get to relax as the recession, restless investors and aggressive Internet competitors put media CEOs under pressure.

Who could forget the photo of Yahoo Inc's (YHOO.O) Jerry Yang at the Sun Valley Lodge last year, with his head in his hands as he tried to fight off an unsolicited takeover bid from Microsoft Corp (MSFT.O)?

This year, investors and analysts say Murdoch and Moonves are among those most under scrutiny, even though all media moguls from Viacom Inc's (VIAb.N) Sumner Redstone to InterActiveCorp/IAC's (IACI.O) Barry Diller are grappling with the sharp slide in advertising spending.

Investors know that an investment in News Corp is a bet on Murdoch the visionary, as well as a wager on Murdoch the unpredictable entrepreneur.

In particular, investors have started to question his love for the struggling newspaper business, best highlighted by the $5 billion acquisition of Wall Street Journal publisher Dow Jones & Co in 2007.

"This is a company that probably has made a couple of deals too far," said Larry Haverty, portfolio manager at Gabelli Global Multimedia Fund. "I think if he swears off the deals, the stock will put on 25 percent."

But Haverty, who said he has known Murdoch for 25 years, doubts there's any chance of the 78-year-old executive would make such a promise.

SHARES UNDERPERFORM

Even Murdoch's purchase of MySpace in 2005, then seen as a bold move into social networking, has failed to deliver the results investors have hoped for. MySpace's once-rapid user growth has slowed and it has been overtaken by Facebook, forcing several rounds of job cuts to reduce costs.

Wall Street is hoping that Chase Carey, the former chief executive of DirecTV Group (DTV.O) who started as Murdoch's number two this month, will be able to guide his boss from making expensive mistakes.

"News Corp is certainly under a lot of pressure, they have a new management team and they have not performed well," said a senior media investment banker, who asked not to be identified because his company competes with Allen & Co.