One lane of the northbound carriageway was closed between junction 32 at Broughton and junction 33 at Galgate.
Four vehicles were said to have been involved in the accident at around 3pm.
The accident was expected to cause severe delays.
Delays after M6 crash in Lancashire
POLICE this afternoon warned of delays on the M6 near Preston after a four-vehicle accident.
By The Newsroom
Thursday, 18th August 2016, 3:25 pm
Updated Thursday, 25th August 2016, 6:09 pm