The 55-year-old rock star was riding a “quad bike,” or all-terrain vehicle, on his Buckinghamshire property when the accident occurred, according to a statement issued by publicist Cindy Guagenti.

His injuries were not considered to be life-threatening, she said.

An examination showed Osbourne broke his collarbone, six ribs and a vertebra in his neck, according to Guagenti. He was in surgery Monday evening at an undisclosed English hospital.

The operation was intended to lift the collarbone, which was believed to be resting on a major artery and interrupting blood flow to his arm. Surgeons also were trying to stem “some bleeding into his lungs,” according to the statement.

Osbourne was taking a day off from promoting the United Kingdom release of “Changes,” a duet with his daughter, Kelly, when the accident occurred.

Guagenti’s office said no further information was immediately available.

“The Osbournes,” the MTV reality show featuring the rocker, wife Sharon and their children, started production about a month ago on its third season, scheduled to begin Jan. 13.

It was not immediately known how the accident would affect production or how or whether it might be included in the series, an MTV spokeswoman said Monday.