My green card is in I-485 for the last 2 years. I have my EAD valid till later this year and also have my H1B (currently in 10th year) valid till Aug 2011. My US based company is sending me on a designation to work in Chennai, India for a period of 1-2 years. I will however remain in US payroll and also have a permanenet address in US. During this 1-2 year period, I will be spending significant amount of time in India but will be travelling back and forth a few times for meetings and projects.

My question is will my H1B remain valid and is there any problem to my green card processing because I will be spending the next several months in India? Is there a minimum amount of time that I need to be in US to keep my H1B valid?