Mumbai, Sept. 12 -- Some of the world's top asset managers and sovereign wealth funds are lining up to pick up a slice of India's largest stock exchange in its upcoming initial public offering (IPO), according to people familiar with the matter. Fidelity International Ltd, Prudential Plc and Singapore's GIC Pte, are likely to participate in the anchor book of the National Stock Exchange of India Ltd's (NSE) smaller-than-planned IPO, the people said, asking not to be identified because the information is private. Abu Dhabi-based Lunate Capital Ltd, Norway's Norges Bank Investment Management, Eastspring Investments-the Asian asset management unit of Prudential-and US's BlackRock Inc are also likely eyeing the portion reserved for anchor investors before the IPO opens to the broader market. Domestic institutional investors (DIIs), including mutual funds and insurers, are also likely to participate in the anchor book, which will close on September 16. The anchor portion is likely to be valued at about Rs.6,800 crore, less than a third of the truncated IPO size, which will comprise entirely an offer for sale (OFS) by existing investors. The allocation of shares to participating institutional buyers will be finalized over the next few days ahead of public subscription, which opens on September 17. The most-subscribed anchor books in India included LG Electronics India Ltd, ICICI Prudential Asset Management Co. and SBI Funds Management Ltd, where anchor investors ended up bidding for a much larger number of shares than those on offer.Participation by large global funds in the anchor book indicates strong institutional confidence and market validation for the IPO, reassuring retail and domestic investors about the company's valuation and growth prospects. BlackRock, Fidelity, GIC, Eastspring and Lunate did not immediately respond to requests for comments. Norges Bank declined comment. An NSE spokesperson also did not respond. Under India's regulations, anchor books open before public share sales, allowing institutional investors to bid for and secure allocations. Shares allotted through the anchor book are subject to post-listing lock-ins, barring investors from selling 50% of allotted shares for 30 days and the rest for 90 days....