Mortgage applications increased 2.5% on a seasonally adjusted basis for the week ended Dec. 16, according to the Mortgage Bankers Association's Market Composite Index.

On an unadjusted basis, mortgage applications were also up week over week with a 2% gain.

The seasonally adjusted purchase index gained 3% from the previous week, while the unadjusted purchase index showed a 0.1% decline from the previous week but a 3% rise from the previous year.

The refinance index gained 3% from the previous week, while the refinance share of mortgage activity climbed to 57.9% of total applications from 57.2% of total applications the previous week.

The FHA share of total applications for the week slipped to 11.5% from 11.6%.