NEW YORK (Reuters) -Microsoft Corp is in talks about an extension of its acquisition contract with video game maker Activision Blizzard, which is set to expire on Tuesday, so the parties can overcome the remaining regulatory hurdles to their $69 billion deal, a person familiar with the matter said on Monday. Nonetheless, Microsoft, which makes the Xbox gaming console, has been seeking the contract extension to ensure that Activision is not wooed by another potential acquirer or has a change of heart, the source said. The terms of the extension under negotiation and whether it would come with more financially advantageous terms for Activision could not immediately be learned.