Yes, export the private key(s) of the addresses that have funds on blockchain.info using the settings/advanced section and then import them into the bitcoin-qt software. You will then have full access to the address(es) in both wallets.
in the bitcoin-qt debug console..
importprivkey "keyhere"
Edit: Don't forget change from transactions may not go back into the original address - so once you've made a transaction it may be that you have to repeat the export & import private key process to have the funds available on both wallets.
What George proposes is correct, however after you successfully import the keys to your
reference clientwallet you should immediately delete them fromblockchain.info, as maintaining the same private keys in more than one active wallets could soon result in weird behavior and unexpected errors, eg if yourref clientis not fully synched when you spend inblockchain.infothe output of one of the imported keys and then you try to send another tx from yourreference clientwhich attempts to spend this very output (double spend) then yourref clientwallet will become corrupted. – George Kimionis – 2014-11-18T18:17:30.427I don't think it would corrupt anything, I've successfully shared keys many times. Though I always wait for everything to sync. There is a chance of a double spend but assuming you don't try to double spend and wait for sync you'll be fine. – George – 2014-11-18T21:02:51.953
@George just because it never happened to you it doesn't mean that this will always be the case for all clients that share parts of their wallets across the network. What if this wallet is controlled by some third-party RPC client that cannot itself realize that it's out of synch and its coin selection algorithm decides to spend an already-spent by another synched wallet with shared keys, what would happen in that case, how would the
reference clientdeal with it? How can you be confident that a double spend will not occur when creating offline transactions in a wallet with shared keys? – George Kimionis – 2014-11-18T21:39:37.593What would happen is the transaction would be broadcast as normal, but quickly rejected by the network. It wouldn't corrupt his wallet.dat and he wouldn't lose any of his keys. Sure, the software may not notice until sully sync'd but I honestly don't see how it would corrupt anything. – George – 2014-11-18T23:20:15.667
1
@George it wouldn't corrupt the
– George Kimionis – 2014-11-19T01:22:22.790.datfile, however it would make the wallet unusable shortly after so please let's stop playing with semantics. Also, please refer to these threads for more on that: http://bitcoin.stackexchange.com/a/3499/11221, also: https://bitcointalk.org/index.php?topic=5324.msg77896#msg77896 and:http://bitcoin.stackexchange.com/questions/490/can-i-use-my-wallet-on-different-computers/509#509semantics? I quote "then your ref client wallet will become corrupted". That comment is the only reason I replied. Anyway, agreed, enough of this thread. – George – 2014-11-19T18:10:40.757