BARCELONA, March 30 (Reuters) - Spanish mobile phone mast operator Cellnex said on Tuesday it launched a 7 billion euro ($8.24 billion) capital hike valued at 36.33 euros per share to fund the acquisition of French telecoms company Hivory. Existing shareholders will have priority in the capital increase, the company said, adding it expects they will subscribe 27% of the new shares. The price of the new shares represent a 22% discount from the closing share price on Monday.