A high-stakes high-tech bidding war that will affect three companies in the Triangle took another unexpected turn Monday.

(NYSE: EMC)) said before the markets opened Monday that it was increasing its bid for (Nasdaq: DDUP) by 12 percent to $33.50 a share, or $2.1 billion in cash.

EMC also removed breakup fees and other potential costs associated with its bid in order to sweeten the offer. It also said its proposal had cleared federal regulatory review.

That news came just as (Nasdaq: NTAP) issued a statement saying it had received federal regulatory approval to acquire Data Domain at $30 a share in a mix of cash and stock.

Monday afternoon, NetApp said it was mulling a response.

"In response to EMC’s revised, unsolicited offer, the NetApp Board of Directors will carefully weigh its options, keeping in mind both its fiduciary duty to its stockholders and its disciplined acquisition strategy. We will provide an update shortly," said Dan Warmenhoven, chairman and chief executive officer of NetApp, in a statement.

(Who will win the battle? .)

NetApp shares closed at $18.85, down 3 cents for the day. EMC closed at $12.89, up 6 cents. Data Domain, meanwhile, closed at $34.06, down 16 cents.

The three firms all have a major presence in RTP.

“The combination of EMC and Data Domain is strategically beneficial to both organizations and, when consummated, will deliver substantial and superior benefits to Data Domain stockholders as well as our respective customers, employees and partners,” said EMC Chairman Joe Tucci

“Over the past several weeks we’ve received strong support from many Data Domain stockholders and customers, validating our belief that EMC is Data Domain’s best choice,” he added. “With regulatory requirements now fulfilled, and in light of the clearly superior proposal we submitted to Data Domain’s Board of Directors today, we expect Data Domain to sign our definitive agreement that will deliver superior value in cash to the Data Domain stockholders in as little as two weeks.”

EMC is based in Massachusetts. NetApp is based in California.

NetApp was forced to increase its bid to $30 a share last month after EMC entered the bidding. NetApp and Digital Domain had agreed to a $25-per-share deal in May.

An EMC-data Domain deal would result in the world’s largest maker of data storage computers, according to Bloomberg news.

Data Domain shares closed at $33.21 on Thursday. That price represents a 75 percent increase so far this year.

In an earlier statement, NetApp said the U.S. Securities and Exchange Commission had approved the NetApp proposal to be formally considered by Data Domain shareholders. A special meeting is set for Aug. 14. The Federal Trade Commission has also signed off on the deal, NetApp said.

"We are pleased to have passed these important milestones, which we believe set us on course for a clear and timely path to close,"  Warmenhoven said. "We continue to believe that our offer is superior to the unsolicited offer from EMC. Not only does NetApp’s proposal provide Data Domain stockholders with attractive short- and long-term value, our combination creates significant advantages for customers and employees, who will benefit from a lower risk of business disruption, continued competition in the marketplace, enhanced products and services, and the complementary nature of our two businesses."