The William Penn Foundation, a major funding source for dozens of Philadelphia-area projects, has suspended new grants to city-related agencies while waiting to hear whether it is covered by the city's lobbying disclosure ordinance.

Last week, the foundation notified the Fund for Philadelphia, a city fund-raising vehicle, that it would not contribute "at this time" to the design of a proposed 1.1-mile trail linking the east and west sides of the Schuylkill.

The foundation's interim president, Helen Davis Picher, said the decision was unrelated to the merit of the Nutter administration's "Bartram's Mile" project, but based on the lobbying ordinance passed by City Council in 2010.

"Due to uncertainty concerning the scope of the city's new lobbying registration and reporting ordinance, and the foundation's ability to monitor and make grants, even indirectly, to support city agencies without registering with the city as a lobbyist or principal, the foundation has suspended new grantmaking to city-related agencies to ensure our full compliance with the ordinance," Picher said in a letter to Ed Fischer, the Fund for Philadelphia's chief executive officer.

"We hope to be able to resume funding projects of city-related agencies in the near future," Picher continued. "We admire and respect the spirit of the city's lobbying ordinance and hope to obtain clarity on the scope of the ordinance."

The move was first reported Monday by Philadelphia City Paper. It grew out of a complaint to the city Board of Ethics filed by Parents United for Public Schools. The group contended that the foundation was required to register as a principal under the lobbying law and disclose more details about its funding of work by the Boston Consulting Group to advise the Philadelphia School District on school closures and other financial issues.

The executive director of the Board of Ethics, Shane Creamer, said he was not permitted to disclose or discuss any pending complaints.

The city's lobbying ordinance requires individuals and organizations seeking to influence public policy to register as principals or lobbyists, and file quarterly reports on what they spend trying to influence legislative or executive decision-making.

The foundation issued a brief statement Tuesday referring to the Parents United complaint. It did not explain its concerns about registering as a lobbying organization and declined to answer questions from reporters.