New Delhi, Infrastructure investment trust India Grid Trust (IndiGrid) on Friday said it has signed a share purchase agreement for the acquisition of 100 per cent units in Virescent Renewable Energy Trust at an enterprise value of up to Rs 4,000 crore for cash consideration. “The Enterprise Value is not exceeding Rs 40 billion (for cash consideration), subject to all other closing adjustments as specified in the definitive documents entered into,” a BSE filing said.