University President Richard Levin announced this morning that he will step down from his position on June 30, after serving 20 years as president.

Levin said in a Thursday afternoon interview that he felt he was in between major projects, with the $5 billion Yale Tomorrow Campaign ending in July 2011 and Yale-NUS not set to open until the fall of 2013. After securing labor contracts this summer with Yale unions, Levin said he began considering stepping down.

“I had been thinking about it, thinking it was one or two more years more, and I think once the labor contract was settled I thought at least it makes it possible to go now,” Levin said.

Levin told the Corporation three years ago that he had several objectives he wanted to complete before leaving Yale — settling the labor contracts, balancing the budget, developing West Campus, launching Yale-NUS in Singapore and starting the new residential colleges.

Of his stated goals, Levin leaves one unfulfilled: Yale still needs to raise roughly $300 million to complete the new residential colleges, a $500 million project.

“The best thing I can do is to raise as much for my successor as I can, to leave some sort of dowry behind,” Levin said. “And depending on who the successor is, it may be a person who has similar experience with this.”

Yale Corporation Senior Fellow Edward Bass ’67 ARC ’72 said in a Thursday morning email that he will write the community “in the near future” with details on the presidential search. The search that appointed Levin took 10 months, though Levin said he expects the upcoming search to only last between four and five.

Yale presidents do not appoint their successors or serve on presidential search committees, and Levin said he will not be formally advising the Corporation on finding his successor, though he may answer questions posed to him by the Corporation.

“I think it’s very important to that the Corporation make decision itself,” Levin said. “I don’t think it’s good for the president or any officer of the University to be very involved.”

Still, Levin said he hopes that his successor will continue the University’s international initiatives, including the college in Singapore and study-abroad programs, and that Yale’s efforts to improve New Haven will be “irreversible.”

Levin said his successor’s biggest challenges will be to continue improving the physical plant and to make major policy decisions on how Yale will approach online education.

“We’re certainly not going to scrap our existing product, but we have to ask what are the things we can leverage successfully in the online sphere, if we want to go there,” Levin said, adding that a faculty planning committee would be assembling this year to discuss Yale’s policies.

Before he leaves at the end of the academic year, Levin said he hopes to continue fundraising and assembling a leadership team for his successor.

Levin served as dean of the Graduate School of Arts and Sciences before his nomination to the presidency in 1993.