The Collaborative International Dictionary of English v.0.48:

ftp \ftp\, FTP \FTP\([e^]f`t[=e]*p[=e]"), prop. v. t. [imp. & p.
   p. ftp'd or FTP'd ([e^]f`t[=e]*p[=e]d"); p. pr. & vb. n.
   FTPing or ftp'ing or ftp-ing
   ([e^]f`t[=e]*p[=e]"[i^]ng).] [acronym from File Transfer
   Protocol.] (Computers)
   To send from one computer to another by means of the standard
   file transfer protocol (ftp); as, he ftp'd me the file
   yesterday. [acronym]

   Note: The participle forms have not been standardized, and
         either lower-case or upper-case may be used, but when
         lower-case is used, either a hyphen or apostrophe is
         used before the ed or ing endings.
         [PJC]