Intercontinental Exchange, owner of the New York Stock Exchange, made a takeover offer for eBay that could value the online marketplace at more than $30 billion.

Intercontinental Exchange (ICE) - Get Report, owner of the New York Stock Exchange, has made a takeover offer for eBay (EBAY) - Get Report that could value the online marketplace at more than $30 billion, a Tuesday media report said.

The report by the Wall Street Journal, which cited people familiar with the matter, sent eBay shares soaring 8.1% to $37.16. ICE was down 5.3% to $94.71.

Intercontinental Exchange had earlier approached eBay and did so again recently, the people familiar told the Journal.

The two companies aren't currently in formal talks and there is no guarantee eBay would agree to a deal, the Journal story said.

ICE is primarily interested in owning eBay's core marketplace business, and not its classified unit, which eBay has been considering selling, the Journal said. The classified unit could go for around $10 billion in a sale.

Meanwhile, the activist investor Starboard Value said earlier on Tuesday that eBay was "deeply undervalued" and called on the company to separate its classifieds business and set up a more aggressive operating plan.

"In order to achieve the optimal outcome, we believe classifieds must be separated, and a more comprehensive and aggressive operating plan must be put in place to drive profitable growth in the core marketplace business,” Peter Feld, Starboard managing member, wrote in a letter to eBay's management and board.

EBay responded that it has taken steps to improve its performance, including new board appointments. It said it also implemented its first dividend while repurchasing $5 billion in common stock, among other measures.

Last year, eBay agreed to sell its ticketing unit, StubHub, for $4.05 billion in cash, under pressure from Starboard and hedge fund Elliott Management.