Proskauer Rose's London office owed the US partnership a total of £13.7m at the end of its 2011-12 financial year, according to UK limited liability partnership (LLP) accounts recently filed with Companies House.

The loan was driven by lateral recruitment, with Proskauer making seven partner hires in London over a 12-month financial period ending on 31 October 2011, as well as its move to new City premises in 10 Bishops Square.

The US funded most of the expansion, with the £13.7m figure, 39% up on the previous financial year end, when the UK LLP owed the US a total of £8.5m.

Proskauer operates several separate partnerships in its international network.

The filing states: "The UK LLP is dependent on continuing finance being made available by the US LLP to enable it to continue operating and to meet its liabilities as they fall due. The US LLP has agreed [...] not to seek repayment of the loan creditor until the UK LLP is in a position to do so."

The firm has made significant investments in the UK over the past two years, bringing in Jones Day heavyweight Russell Carmedy to lead the office in early 2011. Fellow Jones Day partner and global head of private equity Michael Nouril joined alongside Carmedy.

Later that year, the firm brought in a private equity fund formation team from SJ Berwin led by Nigel Van Zyl, who joined alongside fellow partner Oliver Rochman and Kirkland & Ellis funds partner Kate Simpson.

Earlier this year, the firm took on London insolvency duo Mark Fennessy and Hazel Miller from now defunct Dewey & LeBoeuf, following from the New York hire of bankruptcy heavyweight Martin Bienenstock.

The abbreviated accounts also show that partners' capital held within the UK LLP totalled £324,140 at the end of the most recent financial year, down up on the previous reporting period's equivalent figure – which stood at £74,743.