LOS ANGELES (Reuters) - Big-budget action film Transformers: Dark of the Moon won the battle of the box office for the second-straight weekend, generating $140 million (87.5 million pounds) in global ticket sales and pushing its worldwide total since its debut to $645 million, studio estimates showed on Sunday. The third instalment of the popular Transformers films about shape-shifting aliens was the No 1 film in the United States and Canada with $47m in sales.