Preheat oven to 350 degrees. Butter 13x9x2 inch baking dish.Cook pasta in boiling salted until just tender. Drain. Return to pot and mix in ham, tomatoes, feta and mozzarella cheeses, and thyme. Pour cream over. Mix well and pour into prepared baking dish.
Cover with foil and bake 15 minutes. Uncover and stir to distribute cheeses evenly. Cover again with foil and bake another 30 minutes.