Hines vice president David Perry says the Texas-based firm is encouraged by Cellucci's action, which came after considerable debate. Up until the final moment, it was unclear whether the governor would side with Hines and the Boston Redevelopment Authority, or acquiesce to environmentalists and several watchdog groups who claim the exemption will weaken oversight of waterway development.

According to Perry, the change was needed to correct "an unintended consequence of Chapter 91." A road separating South Station from Fort Point Channel would normally have exempted the project from the regulations if it were considered a public way, but because it is technically private due to the presence of a large United States Postal Service operation, the Hines venture falls within Chapter 91 oversight.

"The legislation was essential to enable us to go forward," says Perry, whose firm is proposing a 46-story office tower, 500-room hotel and 400,000-sf of residential uses. Other projects that have come up against the Chapter 91 rules have either been slowed or altered, including the 3.1 million-sf development planned for nearby Fan Pier.