A federal agency is siding with Apple and ordering an import ban on HTC phones that infringe on a patent belonging to the iPhone maker. The U.S. International Trade Commission said Monday that the ban will take effect April 19 so that wireless carriers will have time to adjust their plans. The ITC said in a final ruling that HTC Corp. may import some refurbished phones to offer customers as replacements under warranties and insurance plans. HTC, which is based in Taiwan, is a major maker of phones that use Google Inc.’s Android operating software. Apple Inc. had initially complained about HTC violating several of its patents in April 2010, though the commission narrowed its decision down to just one patent.