BOMBAY, June 29 (Reuters) - Hindustan Motors Ltd. , India's oldest car maker, said it had moved its auto part business to a subsidiary and then raised 2.65 billion rupees ($61 million) by selling stakes in the unit. Following the sale, the two investors -- private equity fund Actis and founder C.K. Birla group -- have invested about 300 million rupees ($6.9 million) in AVTEC, the company said.