This is its highest level since the Building Societies Association started reporting the statistic in January 2010.
Gross lending for the first 10 months of 2011 increased 15% to £19.1bn compared to the £16.6bn lent over the same period in 2010.
October saw £2bn of mortgage approvals by mutual lenders, up 14% on the £1.8bn approved in October 2010.
There was an 18% rise in mortgage approvals for the first 10 months of 2011 at £19.1bn, up from the £16.2bn over the same period last year.
Adrian Coles, director general of the BSA, said: “With the government recently announcing policies that highlight the importance of the housing market to the UK economy, building societies and other mutual lenders continue to play their part supporting homebuyers.
“So far this year, mutual lenders have lent 15% more than in the same period in 2010, whereas other lenders have so far lent 1% less than last year.”
