Sources tell Bisnow that the lenders took an unusual route for SL Green's $1.5B refi of 388-390 Greenwich St Downtown—a floating-rate CMBS loan. (The last time we were this surprised by a 10-digit number was when we got one from that cutie at the bar.)

CMBS is surprising considering Bank of China's presence among the lending consortium (which also included Wells Fargo and Barclays and was led by Citigroup), says CBRE's Shawn Rosenthal (above, receiving a REBNY Ingenious Deal award from Studley's Woody Heller in '09). Bank of China traditionally has been a balance-sheet lender. (China stealing an American lending practice? Is this why Eric Holder accused it of spying on the US this morning?) The deal follows another short-term, floating-rate CMBS loan this year, Deutsche Bank and Bank of China's $675M loan toward Related's acquisition of Time Warner's office space at Time Warner Center, Trepp's Joe McBride tells us. Other CMBS deals this year were 731 Lexington's $300M, floating-rate deal, and ARCP's 82-property portfolio roll-up into a $620M, single-asset securitization.

Citigroup must feel pretty secure about its own book of business, considering it took the lead on the loan for 388-390 Greenwich (above), which is triple-net-leased to itself. The company inked a deal in December to move its global HQs from 399 Park Ave to the 2.6M SF Tribeca building, which it already occupied. When the lease expires in 2020, Citi can extend for 15 years or buy the building for $2B.

Singer & Bassuk’s Scott Singer tells us the size would have been the only challenge to refinancing the property, which replaced an existing $1.1B loan and enabled SL Green to buy out its partner in the building, Ivanhoe Cambridge. Everything else about the property is ideal, he says, from the long-term lease to the creditworthy tenant, the solid reputation of REIT SL Green as the sponsor, the location, and even the aesthetics (both outside and in, once Citigroup finishes interior renovations). Still, the short term of the loan (four years, plus three one-year extensions) makes Scott curious. A private owner intending to hold long-term likely would have taken a long-term deal, he says.