News Corp.

(NWS) - Get Report

rose 4% late Tuesday after the company got some good news about its stock listing.

News Corp.'s nonvoting shares will be added to the

Standard & Poor's 500

index after the markets close Dec. 17, S&P said Tuesday evening.

While it had been expected that News Corp. would be added to the index as part of its recent relocation to the U.S., S&P hadn't set a date for the move. The indexer didn't say what stock would be removed from the index, but indicated it would give three to five days' notice.

David Blitzer, chairman of S&P's index committees, said the third Friday in December -- a day when S&P 500 futures and options will expire -- was chosen for the increased liquidity in the markets that day. While most analysts had expected News Corp. to be added on the futures expiration day, some had expected the changeover to take place on the corresponding day in March.

"We decided sooner was better than later," Blitzer said.

The addition to the U.S. index will trigger News Corp.'s gradual, nine-month withdrawal from stock indices in Australia, where News Corp. has been officially headquartered until this month.

The advance notice that S&P is giving of the change is an acknowledgement of the turmoil the relocation may have on News Corp. shareholders. "This early notice is being given in consideration of the volatility this transition may cause in the market," S&P said in a statement.

The good news comes at a time of unusual turmoil for the media conglomerate. News Corp. recently instituted a shareholder rights plan after shareholder

Liberty Media

(L) - Get Report

made a deal to acquire a large block of its voting shares.

On Tuesday, News Corp.'s nonvoting shares dropped 21 cents to close at $17.63. The voting stock fell 18 cents to $18, then traded at $18.63 after hours.