TIANJIN, China - Three years ago, Gary Biehn, a partner with White & Williams in Philadelphia, wanted to expand his law firm's reach to this port city in northern China, an economic powerhouse that gets special attention from the country's central planners.

The firm already had a business tie to a law firm in Shanghai and saw benefits to connecting with Chinese lawyers here.

Biehn reached out to the International Visitors Council of Philadelphia, and a string of calls and connections that played out over the last year culminated in a business agreement signed here Monday under the eye of Mayor Nutter and his Tianjin counterpart, Huang Xingguo.

Amid high pomp at a signing ceremony at the Tianjin government's guesthouse, Biehn and Li Haibo, founder of the Winners Law Firm, formalized an alliance to help each other's clients. The law firm was one of five Philadelphia groups signing agreements. The others were Drexel University, Fox Chase Cancer Center, the Philadelphia Orchestra, and the nonprofit China Partnership of Greater Philadelphia.

"We have clients who need legal assistance in the United States," said Bai Xianyu, an Oxford-educated lawyer with Winners. "Our firm has been reaching out into international markets, and the most efficient way is through strategic alliances."

For White & Williams, which has 230 lawyers in Philadelphia and 25 in New York, the feeling was mutual. "To assist people in China, you need people who really understand how Chinese law works," Biehn said.

As head of the international practice at White & Williams, Biehn has witnessed rapid change in the quality and number of Chinese law firms. Seeking to build its ties in China, White & Williams formed a strategic alliance with the Xue Law Firm in Shanghai in 2005. A lawyer for White & Williams, Chunsheng "Tony" Lu, who studied law in China and at Widener University, knew lawyers at the Shanghai firm and made the connection.

White & Williams worked with the Xue firm on a dispute later held up as a case study by Chinese law professors and the emerging private equity business here. A private equity fund in Hong Kong had purchased a business in China. When it went to sell the business, a Chinese minority partner wanted to negotiate its own deal - not the way it's done in the West.

The matter went to trial in Shanghai, and Biehn and Lu worked with lawyers from Xue to help litigate the matter. The court ruled in their client's favor.

"That was the first case to test whether Western-style private equity contracts were enforceable," said Biehn, who specializes in equity work.

Next, Biehn set his sights on Tianjin, a showcase city, like Shenzhen in the south and Shanghai's Pudong district, and, conveniently for him, a Philadelphia sister city.

Biehn asked Nancy Gilboy, who, as head of the International Visitors Council, has cultivated ties to Tianjin, if she knew any law firms. The council, supported by the U.S. State Department, fosters international exchanges and runs Philadelphia's sister city program.

Gilboy had a contact: A recent graduate of Temple University's law program in China had recently been a "Sister City Fellow," spending three weeks with the International Visitors Council. He steered her to Winners Law Firm, the largest in Tianjin with 60 lawyers, and she passed on the contact to Biehn.

"They were exactly what we were looking for," Biehn said.

Last February, lawyers from Tianjin traveled to Philadelphia to discuss an alliance with White & Williams, including a meeting at City Hall with Nutter.

A lawyer from Tianjin is spending three months at White & Williams, a general practice firm best known for its insurance and commercial expertise, learning how a U.S. firm operates. Biehn said the two law firms had already begun collaborating. In one instance, a client of White & Williams facing regulatory issues in China received help from lawyers in Tianjin.

Li Haibo, founder of Winners, said the arrangement with White & Williams will help his firm with marketing its services to Chinese clients. "Trust is very important," he said after the signing ceremony. "It's important for our clients to know we have a good relationship with an American law firm."

Chinese clients operate in international trade, insurance, and private equity. "It makes us look good if we have the capability to reach a U.S. law firm within 24 hours," added his partner Bai.