Preferred, also of Conshohocken, plans to spend as much as $350 million to renovate two buildings at the site and build several others for use as offices, restaurants, shops, marinas and housing that would eventually make Rivertown a "24-hour environment," Michael G. O’Neill, Preferred’s chief executive officer, has said.

Synygy’s current headquarters is in Conshohocken’s Lee Park, a landmark former tire factory that Preferred converted into a modern office building. Preferred, which still owns Lee Park, seeks out growing companies and works to keep them in its properties.

Synygy, which develops and sells incentive-compensation software and services, has seen its revenue climb from $1.4 to $14.4 million between 1995 and 1999, according to published reports.

Company President Mark A. Stiffler founded Synygy as a one-person outfit in his home in 1991. It had grown to more than 260 employees last year.

The firm, which has a sales office in Phoenix and an operations center in Bala Cynwyd, more than doubled its total office space to 75,000 square feet when it leased 32,000 square feet at Lee Park in March.

Synygy would double its space again with the move to Chester, where it is expected to occupy 100,000 to 200,000 square feet in the former power station, which will be called The Wharf at Rivertown. The Wharf, with spectacular views of the Delaware River, would house about 300,000 square feet of office space.

Rivertown includes about 90 acres south of the Commodore Barry Bridge owned or controlled by Preferred, all of which sits in the city’s Keystone Opportunity Zone. The state-authorized zone reduces or eliminates most taxes for property owners, residents and businesses through 2013.

Preferred is acquiring the land for $1 from PECO Energy Co., which performed a $12 million cleanup of the site, once home to a variety of heavy industry.

Santorum heads a long list of government and business officials scheduled to take part in the formal announcement of Synygy’s plans tomorrow at Chester Station.

Two representatives of Gov. Tom Ridge are expected to appear, including a senior official in the state Department of Community and Economic Development and a member of the Governor’s Action Team.

Both agencies offer businesses public subsidies that are promoted as economic development. Some critics have labeled the taxpayer-funded aid corporate welfare.

To contact Erik Schwartz, e-mail eschwartz@delcotimes.com