Linklaters has climbed to the top of the global and Asia-Pacific M&A rankings by value for the first half of this year, with roles on a string of high-profile deals, putting the firm comfortably ahead of its nearest rivals.

Research carried out by Legal Week data partner Mergermarket shows Linklaters advised on the greatest value of global M&A deals over the six-month period ending 30 June, with the firm acting on 121 deals with a combined value of $380.8bn (£193.6bn).

In contrast, at the end of 2007 the firm was only in fifth place by value, with Wall Street leader Sullivan & Cromwell leading the rankings. Jones Day tops the global tables by volume with roles on 158 deals over the period.

Meanwhile, active Asian markets have also helped propel Linklaters' Asian corporate practice to the top of the regional tables, with the firm advising on 20 deals worth $272.3bn (£138bn) at the half-year point. Top M&A instructions for the firm in the region include a role in the restructuring of the Chinese telecommunications market, with the firm acting for China Netcom throughout its $72bn (£36.6bn) merger with China Telecom.

Linklaters Asian managing partner Giles White said: "There is a lot of inbound M&A activity and clients want deep coverage in key jurisdictions. Linklaters is significantly placed because we combine international expertise with local practices in key markets like Beijing, Hong Kong and Shanghai."

The tables show how well activity levels in Asia held up during the first half of 2008 despite the downturn elsewhere. Deal value in Asia increased, with the region seeing $235.4bn (£119.7bn) of deals in the first half of this year, compared with $210bn (£106.8bn) for the same period last year.

Slaughter and May Hong Kong corporate partner Benita Yu said: "The US market is weak, the European market is slow and the Asian market is strong – this is a good time to do acquisitions and the Chinese are in buying mode. But stock markets have been a rollercoaster and it is difficult to gauge the rest of the year."

Slaughters placed fourth by value in the Asian markets, climbing from 50th at the year end, and came seventh in the global rankings by value. By volume, deals in Asia fell only marginally between H1 2008 and the same period last year. Globally, the M&A market took a more dramatic hit, falling from 7,701 deals in H1 2007 to 6,253 in H1 2008.