»»How To Transfer Miles Between United Mileage Plus and Continental OnePass
United and Continental offer the chance to easy transfer your award miles between their two frequent flyer programs, Mileage Plus and OnePass. That means If you want an award ticket on United but don’t have enough Mileage Plus miles, you can move miles from your OnePass account to make up the difference, or vice versa.
You can transfer miles only once per day, in 1,000-mile increments with a limit of 200,000 miles per transfer.
If you change your mind, you can wait 24 hours and move the miles back into their original account.
Transferring miles does not consolidate your accounts.
You can also combine your elite activity; if you are an elite member of one program, you can be an elite member of both. However when you register, you have to designate either your Mileage Plus or OnePass account as your primary account for upgrades for the year.
If you can opt to leave your miles in both accounts, your accounts will not be combined until the end of 2011, when United Mileage Plus and Continental OnePass will be combined into a single program. (source)
