It’s Wall Street’s version of the odd couple.

The deal yesterday between Howard Lutnick’s financial brokerage BGC Partners and real-estate adviser Newmark Knight Frank is certainly raising eyebrows on Wall Street.

The planned purchase would see BGC, which specializes in helping clients buy and sell complex derivatives, currencies and other financial products over the phone, acquire the US operations of Newmark Knight Frank, a commercial real-estate advisory firm.

“This is the beginning of a dramatic new footprint in commercial real estate by BGC, and the definitive starting point of BGC’s strategy to grow in this sector,” Lutnick said in a statement.

However, two analysts who spoke with The Post but asked to remain unnamed, said they could not immediately identify the merits of the BGC purchase.

“We’re kind of in the dark on this one and the company has given us little information to work with,” said one analyst.

Indeed, scant details were offered about the transaction, including the price. BGC, which said the acquisition would immediately boost profits, saw its shares jump 3.9 percent yesterday.

A spokesman for BGC declined comment.

Sources told The Post that Newmark Chairman Barry Gosin and Lutnick maintain a close relationship and hatched the deal over the past several weeks. Lutnick is also the CEO of boutique investment bank Cantor Fitzgerald, which recently launched an effort to break into the complex business of turning mortgage loans into securities.

However, it’s unclear if the combined BGC-Newmark wants to be able to boost the ability to help sell products like commercial mortgage-backed bonds to its clients along with foreign exchange securities and derivatives.