The University and the government of Peru have agreed to extend negotiations for a second time over the title to a collection of Incan artifacts brought to New Haven nearly a century ago from Machu Picchu by the explorer Hiram Bingham III, Yale officials told the News Sunday.

After years of controversy, Yale and Peru announced Sept. 14 that the two parties had agreed to acknowledge Peru’s title to most of the artifacts in question and that Yale would eventually return most of the collection. At that time, the University and Peru set a 60-day timetable for reaching a final agreement regarding the objects. But 60 days came and went, and the two parties agreed on a 30-day extension, which ended Friday.

Yale officials said last week that it was unlikely an agreement would be reached by Friday because internal issues within Peru had delayed negotiations.

Indeed, no agreement was struck, Yale officials said Sunday night, but declined to comment on the reasons for the extension. Instead, the University and Peru have once again agreed to extend negotiations, Yale spokeswoman Helaine Klasky said. Although Klasky did not indicate the length of the extension, she said the two parties have not abandoned the principles agreed upon in the Sept. 14 announcement.

In an interview Sunday night, Yale President Richard Levin said he remained hopeful that the University would soon reach an agreement with Peru.

“We have more time,” Levin said. “We’re still working, and we’re still optimistic.”

Levin declined to elaborate further.

“Both Yale and the Government of Peru remain committed to the agreement,” Klasky wrote in an e-mail.

Despite recent postponements, both Yale and Peruvian officials said last week that they were nearing an end to their negotiations. Fernando Cantuarias, legal counsel to Peru’s Housing Minister and lead negotiator with Yale Hernan Garrido-Lecca, said Thursday that a final agreement between the two parties would probably be reached within the next two weeks.

Peruvians have long maintained that the objects should be returned to the South American nation. Yale and Peru signaled an end to the long period of tension and recent threats of litigation from Peru this year when the two parties began to negotiate formally.

This development followed last year’s election of Alan Garcia as Peru’s new president and a letter Levin sent to Garcia this spring in which Levin said he emphasized his eagerness to put an end to the long-standing disagreement.

After Garrido-Lecca led a delegation to Yale in September, it seemed that a final agreement was not far off. University General Counsel Dorothy Robinson told the News on Sept. 15 that the two parties would work toward a formal agreement within 60 days.

But despite the enthusiasm from Yale and Peruvian officials after the visit, the original deal has met with some resistance within Peru, Dan Martinez, attache to the American ambassador to Peru, said last week.

“I think once [Garrido-Lecca] returned and announced that this had been agreed to and the terms became public knowledge, some in the local community had questions and concerns about some of those provisions,” Martinez said.

Garrido-Lecca, his legal counsel Fernando Cantuarias and Martinez could not be reached for comment from Peru on Sunday night.

Archaeology professor Richard Burger, the co-curator of a show at the Peabody Museum in 2003 that featured many of the artifacts, said Thursday that Yale is willing to return almost all of the museum-quality pieces in the collection.

An undetermined number of fragmented pieces will remain at Yale for 99 years, Robinson said in September. Burger said Thursday that it is important for these pieces to stay at Yale for further research and as a testament to Yale’s long-standing connection with the objects.

According to the September statement, Yale would also co-sponsor an exhibition of the objects that would travel globally and help Peru develop plans for a museum to showcase the objects near Machu Picchu.

Burger told the News last week that one reason for the delay in the negotiations could have been the damage caused by an August earthquake in Peru.

Garrido-Lecca, as the nation’s housing minister, has had to spend much of his time focusing on rebuilding his nation, Burger said.

Bingham rediscovered Machu Picchu in the early 20th century while on a Yale-sponsored exhibition. The Inca town had been abandoned for centuries.