Negotiations next week between the owner of the Hilton Pittsburgh hotel, city officials and the renovation's architect may decide the future of the construction project, which encountered its latest complication this week.

Work on the Hilton, Downtown, was halted Thursday after the city's Bureau of Building Inspection revoked the building permit.

Architect Stephen Berry, owner of Youngstown Design Co. in Youngstown, Ohio, had written to city building inspection officials earlier in the week asking for the return of his design plans and specifications, without which work cannot proceed on the site.

"It's a matter of monetary issues," said Mr. Berry. He said his firm has not been paid in months for work on the $25 million renovation project and has filed mechanics' liens totaling $308,575 against the hotel's owner, Shubh Hotels, of Boca Raton, Fla.

"If we're not paid for our drawings, then we prohibit them from building the additions and renovation work," he said.

State construction code stipulates there must be a design professional working on the site for construction to proceed, said city Solicitor George Specter.

Mr. Berry said he did not plan to resume work until he is paid in full but said he had a "positive conversation" Thursday with Shubh Hotels CEO Atul Bisaria.

He said the hotel executive claimed to have arranged new financing and hoped to have all companies paid soon. Mr. Bisaria, in a later interview, said he could not comment on that.

The two men plan to meet Monday to reach an agreement, said Mr. Bisaria. He would not specify whether he planned to make payment at that time.

Mr. Bisaria also plans to meet with Mayor Luke Ravenstahl Wednesday to "discuss the actions to take to clean up the outside of the Hilton to welcome the world in September," said mayoral spokeswoman Joanna Doven.

She said Shubh Hotels would have to reapply for the building permit, which costs around $30,000.

Asked whether the exterior renovation will be completed by the G-20 summit, Mr. Bisaria responded, "We will try."

To complete the project by then, though, would be "next to impossible," Mr. Berry said.

The situation is the most recent of the Hilton's many difficulties over the past 18 months. Seventeen mechanics' liens have been filed against Shubh Hotels, which Mr. Bicaria said would be settled on an ongoing basis.

Shubh Hotels recently paid two creditors, Salego Plumbing Co. in Shaler and Days Inn in Banksville, a move that averted a sheriff's sale of the Hilton's furnishings originally planned for Monday.

Work on the construction project was stalled twice in the past year when West Mifflin-based prime contractor P.J. Dick Inc. pulled its workers due to nonpayment. Though the $317,273 debt was settled earlier this month, work did not resume.

The renovation-expansion project began in 2006 and included new carpeting, ceilings and flat-screen televisions, and the addition was to include a glass-enclosed swimming pool and expanded banquet facilities.

So far, Mr. Berry said, the restaurant, lounge, some meeting rooms and all 700 guest rooms have been renovated, and a part of the steel framing on the addition has been completed.