The parks department said in a statement that the city was "not party to this disagreement," which it said was between the union and Mr. Poll, whom it identified only as "a restaurant operator with a concession to operate in Central Park".
Two chains operated by Gondola Holdings, the country's biggest restaurant operator, Zizzi and Ask, also use a portion of the gratuities added by customers on credit and debit cards to pay the minimum wage.
NEW YORK TIMES BITS Restaurant Operator Sets Price Range for I.P.O.
It is the largest single-brand restaurant chain and the largest restaurant operator globally.
According to the company's prospectus, the restaurant operator initially struggled after its leveraged buyout.
Yoshinoya, a chain restaurant operator that features beef, fell 2.6percentto to 150,000 yen.
Among the firm's acquisitions in Japan are Skylark, a big restaurant operator, and Bellsystem24, a major call center company.
Chang's China Bistro, the Asian-themed restaurant operator, has agreed to go private in a deal valued at $1.1 billion.
The restaurant operator may also be chosen to run the 24,000-square-foot observation deck on the 102nd floor.
The restaurant operator gained fame in part through offerings like the "bloomin' onion," a deep-fried onion blossom with a gut-busting 1,948 calories.
The case filed by China's biggest restaurant operator comes as the government intensifies a campaign to clean up rumors on social media.
