PT Indocement Tunggal Prakarsa said it hopes to increase its annual production capacity to 16Mt after the completion of its revamping program.    The company is upgrading one of its factories to increase its production capacity by 600,000tpa from 15.42Mt at present, company Finance Director Christian Kartawijaya said.   Christian said the program will cost around US$15m, adding the company is set to continue the program to expand its annual capacity by 4Mt in the next several years.   He also predicted that the country’s cement production will be flat this year revising earlier prediction of 3 per cent growth pointing to a 4 per cent decline in domestic consumption in the first quarter of this year.