NEW YORK (AP)  -- A 400-foot-long wall in a corner of ground zero rekindled a bitter feud Wednesday between the owners and developer of the World Trade Center site, in a $300,000-a-day dispute over who should take it down.

The Port Authority of New York and New Jersey told developer Larry Silverstein this week that it had finished digging up land it had promised to deliver so Silverstein could build the third of three towers he plans at the site. The agency in February finished work on another parcel it had promised to excavate.

The agency was late delivering both sections of land and has paid nearly $44 million in $300,000-a-day penalties to the developer, who is paying the agency $78 million a year in rent on the undeveloped site.

The agency said it had finished everything it had agreed to do on Sunday.

``We have delivered the site to Mr. Silverstein,'' the agency's executive director, Christopher Ward, said Wednesday.

Janno Lieber, who heads the trade center rebuilding project for Silverstein, said the steel-and-timber retaining wall has yet to be removed and is the agency's responsibility. The wall sits on the western border of one of the three planned office towers. He also said the agency has to install supports in a retaining wall built around the largest planned office tower.

``Our agreement calls for the PA to provide us with 'construction ready' sites, which is not what they delivered,'' Lieber said in a statement Wednesday.

Lieber said the Port Authority didn't let Silverstein know until Tuesday that it had finished work on the site and would no longer be paying the fees.

"It is unfortunate that the PA has failed to live up to their obligations, but we are confident this will be corrected after the matter is presented to an independent panel of arbitrators charged with resolving these types of disputes,'' he said.

The Port Authority said the wall, about 40 feet high and 400 feet long, is not within the tower footprint that it agreed to turn over to Silverstein.

The agency and Silverstein have sparred before about who should build the 10 million square feet of office space from the trade center and how to split billions in rebuilding money. Publicly bitter talks dragged on for four months before the agency and Silverstein made a deal two years ago that split their roles in the rebuilding process.