Real estate investors are bracing for a bidding war over New York City’s iconic Empire State Building.

The city’s second tallest skyscraper is owned by Malkin Holdings, which plans to launch an initial public offering for a real estate investment trust (REIT) that includes the famous building. In regulatory filings, the company says it has received two outside bids for the skyscraper, Bloomberg notes.

A consortium of unidentified Middle Eastern investors has partnered with two New York-based investors, Philip Pilevsky and Joseph Tabak, to make a $2.1 billion all-cash bid for the building. That reportedly tops a $2 billion offer from Rubin Schron, a local investor.

Malkin Holdings says it is reviewing the new bids and will consider all its options. The company has previously valued the Empire State Building at $2.53 billion. If the IPO goes forward, the REIT that includes the building would trade under ticker symbol of “ESB.”

The 1,454-foot-tall skyscraper was built in 1931 and remained the world’s tallest building until 1972 when the World Trade Center’s (WTC) North Tower was completed. After the destruction of the WTC by Middle Eastern terrorists in 2001, the Empire State Building regained the title of New York’s tallest building until last year when One World Trade Center surpassed it in height.

Last year, the building received an updated LED lighting system that allows it to illuminate its soaring spire in a greatly expanded array of colors.