Clifford Chance (CC) has reported a 9% drop in the number of pro bono hours carried out by its lawyers during 2011-12, with the firm placing a value of £17m on the time invested over the financial year.

According to the firm's annual corporate responsibility report, CC's lawyers around the world invested 50,324 hours in pro bono and community work during 2011-12, down 8.5% on the 2010-11 figure of 55,021.

The firm's London lawyers recorded a full-time equivalent average of 32.7 pro bono hours, down from 34.7 in 2010-11 – a higher figure than the firmwide fee-earner average of 16.7, which was down 11% from the equivalent figure of 18.8 last year.

The report states: "The reasons are varied and, in the UK, included the closure of Law For All, the not-for-profit solicitors with whom we had delivered the bulk of our pro bono social welfare law services over the last 10 years.

"This coincided with extremely high levels of client activity in some of our key regions such as Asia-Pacific and the US, which has absorbed resources."

Law For All went into administration in July last year, with the collapse attributed to "changes to the administration of publicly funded legal work". In November 2010 CC had pledged to provide pro bono support worth £1m to the legal aid practice over a five-year period.

The corporate responsibility report sets out new targets for the firm, which include a goal to increase the proportion of lawyers providing pro bono services from 48% to 60% by the end of 2013-14, alongside a target of 51,000 pro bono hours for 2012-13. CC is also aiming to increase the number of partners leading pro bono relationships from 55 to 64 by year end.

The report also breaks down gender representation at the magic circle firm, which has a 15.3% female partnership, 49.1% female fee earners and 70.5% female business support staff, with the partnership proportion slightly up on last year's figure of 14.5%. CC has a long-term ambition to reach at least 30% female representation among its partners.

Diversity figures in the report also show the firm has 6.1% ethnic minority representation among its London partnership, compared to 13.1% among lawyers and 12.2% among business services staff.