It has just come to light via an interesting post at Information Week by Paul McDougall that Nvidia and Microsoft have a bit of a deal going on regarding any future acquisition of Nvidia.

Apparently in order to make itself less of an appetizing takeover target Nvidia has agreed with Microsoft that the company from Redmond would have first rights to match any offer of 30% or more that any company might make for outstanding Nvidia shares.

This is according to a recent SEC filing

“Under the agreement, if an individual or corporation makes an offer to purchase shares equal to or greater than 30% of the outstanding shares of our common stock, Microsoft may have first and last rights of refusal to purchase the stock,” Nvidia said in the filing, dated May 27.

The pact puts Redmond in a position to effectively veto attempts by any of its rivals to snap up Nvidia, which makes key components for the red-hot tablet market, which includes forthcoming Windows 8 slates.

Now apparently this is an old pact that is still in effect and was part of the broader agreement where Microsoft licensed the Nvidia graphics chip for the Xbox. Even though ATI has provided the graphics chips since 2003 the acquisition agreement part is still in effect.

By current valuations this pact would kick in should any potential suitor offered about $3.4 for 30% or more of Nvidia.

As Electronista points out this a good deterrent against companies like Apple who might have an interest in buying Nvidia

That the pact is still ongoing would also be a possible deterrent against companies like Apple that might use NVIDIA as a weapon against Microsoft both on desktop and in mobile. It could get a genuinely Mac-optimized graphics option while dropping all Windows support, and it could take NVIDIA’s Tegra line away as an option for Windows 8 tablets while using the better parts of the ARM chip for Apple’s future iPads and iPhones.

[Cross-posted at Winextra]