LONDON, May 3 (Reuters) - Johnson Controls International is considering the sale of its ADT alarms business as it offloads some non-core businesses, three people familiar with the matter told Reuters.

The unit of the New York-listed building manufacturer operates in Europe and Latin America and has already drawn interest from private equity funds, said the people, who spoke on condition of anonymity.

The preparations are at an early stage and a sale process could happen towards the end of the year, one of the people said.

The alarms unit could fetch a valuation of less than $1 billion in the event of a sale, the person said. Johnson Controls does not break down financials for the unit.

"We constantly evaluate ways to improve our business and serve our customers better; however, we don't comment on rumor or market speculation," a spokesperson for Johnson Control told Reuters.

(Reporting by Andres Gonzalez, Amy-Jo Crowley and Anousha Sakoui; Editing by Emelia Sithole-Matarise)