HONG KONG, Sept 22 (Reuters) - IMAX China Holding Inc, majority-owned by the namesake giant screen movie theater equipment maker, launched on Tuesday a Hong Kong initial public offering worth about $280 million, tapping five cornerstone investors to help fund the deal, according to a term sheet of the deal seen by Reuters.

The company and shareholders including its parent IMAX Corp are offering 62 million shares in an indicative range of HK$29.80 to HK$34.50 each, putting the deal at up to HK$2.14 billion ($276 million). The IPO may grow to nearly $317 million if the company exercises an option to meet additional investor demand for the deal.

Five cornerstone investors agreed to buy $55 million worth of shares, helping secure demand for the deal before it was launched to retail and other institutional buyers, a source with knowledge of the IPO said.

($1 = 7.7500 Hong Kong dollars) (Reporting by Elzio Barreto; Editing by Michael Perry)