mumbai, Aug. 15 -- National Highways Infra Trust (NHIT), the infrastructure investment vehicle of India's highways developer, is planning to raise up to Rs.9,000 crore through private bond placements to refinance debt and cut borrowing costs, two people aware of the matter said. The fundraise will kick off in the coming two to three months, these people added. The move comes as top-rated issuers increasingly tap the bond market to capitalise on falling yields. Currently, the trust has about Rs.21,700 crore of outstanding debt-mostly bank loans-with a blended cost of borrowing around 8% per annum. The loans are from State Bank of India, Punjab National Bank, Axis Bank and IDBI Bank, among others, per data from Care Ratings Ltd. NHIT can prepay up to Rs.9,000 crore of bank loans without attracting pre-payment penalties, one of the persons cited above said, requesting not to be identified as the fund-raising discussions are private. The second person said the trust is likely to raise most of the money as zero-coupon bonds (ZCBs) with staggered maturities of three to 10 years to avoid all of them coming due at the same time. ZCBs are issued at a deep discount to face value and redeemed at face value, with no periodic interest payments.Brokers have already started pitching some of these bonds to insurance companies, the second person said. The trust currently has outstanding zero-coupon bonds worth Rs.2,031 crore.The first person cited above said that the plans are still at an early stage and may change depending on market conditions....