Mumbai, May 30 -- Nearly 150 employees in mid-level and regional operations at Ecom Express have already resigned, while CEO Ajay Chitkara and some other senior staff are expected to leave after the Competition Commission of India approves Delhivery's acquisition of the company, two people familiar with the matter told Mint. In February, Ecom Express had laid off at least 500 employees after pausing its plans for an initial public offering (IPO). Before that it had about 15,600 employees and associates, and delivered goods to more than 27,000 pin codes, according to the company's website. "CCI's approval is likely to come through in the next 45 days," said one of the people, adding that several employees have resigned voluntarily. "Lot of r...