HSBC Bank USA, one of downtown Buffalo's premier companies, is considering moving out of

the city's tallest building, potentially leaving a huge hole in downtown's corporate fabric.

The U.S. subsidiary of London-based HSBC Holdings PLC is exploring the property options for

its vast Buffalo operations, putting its extensive downtown presence at risk. The bank employs

6,000 in Western New York, including 4,000 in Buffalo.

Buffalo's largest bank, whose red and white logo adorns the top of the 38-story building,

has issued a formal "request for proposals" to area property owners and developers, seeking

alternatives to its current location at the HSBC Center.

The bank has not decided to leave the tower, where it has been for decades, but its lease

expires in October 2013. So "as part of standard business practice," the company wants "to

review how its future real estate requirements in Buffalo will best be met," said spokesman

Neil Brazil.

The company still has an option to extend its current lease in the tower by mutual consent

of the bank and property owner Seneca One Realty LLC.

"The company is currently looking at a range of options, one of which is to maintain the

status quo," Brazil said. "We're still in the early stages of this process, and a final

decision is not expected for some months."

However, Brazil downplayed the significance of the property evaluation, saying that it's a

continuing process. "This is really standard business practice that all corporations do from

time to time," Brazil said. "Taking a look at our corporate real estate options is just one of

the reviews that we carry out."

HSBC, formerly Marine Midland Bank, is by far the largest tenant in the building, occupying

floors 7 through 27 as well as 29 in the tower, along with all the ancillary buildings that

wrap around the tower. The bank, which has been in the building since 1972, occupies 653,000

of the 1 million square feet.

That makes it "pretty darn important" to the city, said Keith M. Belanger, chairman of

Buffalo Place. "They're one of the big anchors in downtown," he said. "They anchor the

building, and they anchor downtown."

Even if the bank chooses to move elsewhere downtown, it could still hurt the tower and

downtown. That's because if the new project is heavily subsidized through tax breaks and other

benefits that yield lower rents, the tower and other older facilities in the business district

couldn't compete. "You'll have the overhanging space from the tower," Belanger said.

Adding to Seneca One's potential woes, the other major tenant in the building — law

firm Phillips Lytle LP — is also reviewing its real estate options, as its own lease

expires in December 2013. It has retained Studley Group, a property search advisory company

specializing in law firms, to help with its own search.

Seneca One Chief Operating Officer Stephen P. Fitzmaurice declined to comment, citing

nondisclosure agreements that developers and property owners had signed.