Microsoft said Friday it had signed a deal with the Chinese government to give Beijing limited access to the source code for its Windows software.

The announcement was made during a visit to Beijing by company chairman Bill Gates, making China the third country to sign such an agreement with the company after Britain and Russia. NATO has also signed on.

Microsoft hopes the deal will give the Us technology giant a greater share of the rapidly growing Chinese market, where rival Linux -- which can be modified for free -- has already made inroads.

"It's really quite surprising to some people that we are sharing all the information we have, including the entire source code, as part of this. But it's part of the commitment to make sure that governments and industry are working together in the best possible way," Microsoft chairman Bill Gates said at the end of his two-day visit to Beijing.