SAN FRANCISCO, April 16: The hard feelings between Facebook Inc. founder Mark Zuckerberg and a former college classmate have boiled over into another legal dispute, this time over the popular online hangout’s trademark.

In a petition filed on Tuesday with the US Patent and Trademark Office, Aaron Greenspan is seeking to cancel Facebook’s legal claim to its name.

Greenspan, 25, argues Zuckerberg, 23, had no right to trademark the Facebook name in 2005 because the term had been used generically for decades at Harvard University, where they first met. What is more, Greenspan maintains he used the term “Face Book” as part of an online service called houseSYSTEM a few months before Zuckerberg unveiled his now-famous website in 2004.

The former Harvard classmates are now both building companies in Palo Alto with differing degrees of success. Greenspan’s software venture, Think Computer Corp, has not caught on quite like Zuckerberg’s Facebook, which boasts 70 million users worldwide.

This is not the first time legal questions have been raised about whether Zuckerberg came up with the idea that blossomed into one of the Internet’s hottest companies and made him a billionaire in the process.

A trio of former Harvard students have been fighting over Facebook’s origin since 2004, alleging in a federal lawsuit that Zuckerberg stole the social networking concept after they hired him to work on a website that eventually became ConnectU.

Facebook reportedly is nearing a settlement with ConnectU founders, twin brothers Cameron and Tyler Winklevoss and their partner, Divya Narendra. The New York Times reported the confidential settlement talks earlier this month.

Long before Zuckerberg moved to Silicon Valley in 2004, the Facebook term was widely used at Harvard to describe any paper or electronic book that displayed the faces of students and faculty “in a structured manner,” Greenspan wrote in his petition.