NEW YORK — The Internal Revenue Service can demand information from UBS AG about US clients of Wegelin & Co., the Swiss bank that pleaded guilty this month to conspiring to help cheat the IRS, a US judge ruled.

US District Judge William H. Pauley III signed an order in Manhattan federal court that authorized the IRS to serve a summons on UBS, the largest Swiss bank. The tax agency seeks records of Wegelin’s correspondent account at UBS, according to the Jan. 25 order announced Tuesday.