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 roles will become redundant after the acquisition so there will be employees opting out, establishing higher cost savings," the second person said. A spokesperson for Ecom Express said the company was not in a position to comment while it awaited regulatory approval. Delhivery, too, said it had no comment on the matter, while Chitkara did not immediately respond to Mint's queries. During Delhivery's earnings call this month, CEO and managing director Sahil Barua said, "The regular attrition in Delhivery's network itself will provide us sufficient room to absorb all qualified staff from Ecom Express in our operations around the country." He added that they would undergo rigorous training during the onboarding process, and that the purchase consideration included about about Rs.300 crore in integration costs. In April, Delhivery announced it had signed a definitive agreement to acquire a controlling stake in Ecom Express Limited for about Rs.1,400 crore in cash. Less than a year ago, Ecom Express was valued around Rs.7,000 crore....