NEW YORK, June 27 (Reuters) - SL Green Realty Corp's shares rose on Tuesday, extending gains from the previous session, after some research analysts heaped praise on the real estate investment trust (REIT) for selling a 50% stake in one of its prime New York City office buildings.

SL Green announced on Monday that it had sold the building at 245 Park Avenue to a U.S. subsidiary of Japanese real estate developer Mori Trust Co Ltd at a $2 billion valuation, sending its stock up nearly 20%.

Barclays analysts, which have an "underweight" rating on SLG, raised their price target for the shares to $26 from $22, saying in an investor note that the deal is an "unambiguously positive signal for well located, high quality office assets like 245 Park."

The transaction is a "significant milestone" for SL Green given that it represents nearly half of the planned asset sales for 2023 and more than covers the company's share of redevelopment costs, said BTIG analysts, who reiterated their "buy" rating.

Analysts at Scotiabank, who rate SLG a "sector underperform", hiked their price target for the company's shares, calling the transaction "positive." But they also warned of "likely limited cash infusion from the deal for SLG" and cited "the heavily leveraged capital structure of the building."

SL Green's stock jumped 11% on Tuesday to a high of $31.35 per share. Through the market close on Friday, the company's stock had lost about half its value over the past one year and roughly 70% since the beginning of 2022.

245 Park Avenue is a high-end "Class A" property located in mid-town Manhattan near the Grand Central Terminal, housing several financial firms including Ares Management, Angelo Gordon, and Societe Generale.

The stake sale represents a slight discount to the $2.21 billion China's HNA Group paid to acquire the building in 2017 when New York City's commercial real estate market was at its peak. SL Green took control of 245 Park Avenue last year after lenders seized the building from HNA Group.

(Reporting by Chibuike Oguh in New York; Editing by Lisa Shumaker)