NEW YORK ( TheStreet) -- Zynga ( RIMM) shares plunged, falling 8.02% to $2.41 in premarket trading Friday, as the social gaming company and its largest partner, Facebook ( FB), amended terms of their agreement allowing them to seek other partners. In a regulatory filing after the close Thursday, Zynga and Facebook amended their agreement so that Zynga will no longer have to display Facebook ads or use Facebook payments on its own Zynga.com properties. Under the amended deal, Facebook can also develop its own games. "Zynga will no longer be separately obligated to display Facebook ad units or implement Facebook credits on any such Zynga game pages. In addition, the Addendum No. 1 Amendment provides that Zynga's right to cross-promote any games that are off of the Facebook web site from Zynga services that use Facebook data and to use e-mail addresses obtained from Facebook, will be limited by Facebook's standard terms of service, subject to certain exceptions," the 8-K filing said. Facebook shares tacked on 0.51% to $27.46 in early Friday trading. Splunk ( SPLK) shares fell 1.03% to $29.67 despite beating Wall Street expectations for the third quarter. The software company generated $52.05 million in third-quarter revenue, up 67% from a year earlier. License revenue increased 56% to $34.5 million. On a non-GAAP basis, Splunk lost 1 cent per share. Analysts were looking for a loss of 2 cents per share on $46.67 million in revenue. Fourth-quarter revenue also exceeded Wall Street estimates. The company expects sales to be between $58 million and $60 million, with non-GAAP operating margins between 3% and 4%. Wall Street analysts expect $58.07 million in revenue. Apple ( AAPL) shares were active in premarket trading, gaining 0.17% to $590.39 as the new iMacs announced in October are now available for sale. The sleek new addition to Apple's Mac lineup, the iMac comes in both a 21.5-inch and 27.5-inch version. The smaller 21.5-inch version starts at $1,299, and comes with Intel's ( INTC) 2.7 GHz quad-core i5 processor. The 27.5-inch version starts at $1,799 and comes with a 2.9 GHz quad-core i5 processor.