Law firms are cashing in after a leading legal survey showed that M&A activity in Australia more than doubled in 2010.

According to Thomson Reuters, the value of announced M&A deals in Australia for 2010 totalled $US164.4 billion ($165 million), up from $69.1 billion in 2009.

This was the highest recorded volume of deals since 2007.

"The nature of the work has changed back to classic M&A," Freehills corporate partner Rebecca Maslan-Stannage told Lawyers Weekly. "We were busy with restructurings and capital raisings the previous year, but for pure M&A deals, 2010 was definitely stronger, and encouragingly, the year finished strongly."

It was mainly the top-tier firms that benefitted from the increased activity, with Clayton Utz topping the Thomson table on announced deals with a 27.8 per cent market share, pipping Mallesons Stephen Jaques (24.4 per cent) and Freehills (23.7 per cent). Blake Dawson and Allens Arthur Robinson, which was ranked first last year, rounded out the top five.

The only firms in the top 10 that didn't increase their market share were Freehills (-8.5 per cent) and Allens (-16.4 per cent).

The big improver in the table was Norton Rose, which jumped from 31^st to seventh position, and North American firms Sidley Austin (88^th to ninth) and Stikeman Elliot (72^nd to 10^th).

In terms of the number of deals completed by value, Allens finished ahead of Mallesons and Freehills.

The Thomson survey found that there was a 23 per cent increase in worldwide M&A in 2010 as compared to 2009.

Skadden, Arps, Slate, Meagher & Flom and Sullivan & Cromwell were the leading firms for worldwide announced M&A deals in 2010.

In the Bloomberg legal tables, West Australian firm Steinpreis Paganin joined the top-tier at the top of one of the surveys.

Steinpreis Paganin topped the Bloomberg Australia/New Zealand Equity IPO Issue Advisers table by volume, acting on 12 IPOs for the last calendar year. That was more than twice the number of IPOs (5) of the next best firm, McCullough Robertson.

When it came to ranking firms by value, Mallesons came out on top, comfortably ahead of Minter Ellison and Allens.

Mallesons also topped the Bloomberg M&A Legal Advisory League Table for announced deals in the Asia-Pacific (excluding Japan) in 2010, acting on deals worth a combined total of around $US57.7 billion.

Mallesons finished comfortably ahead of Clayton Utz ($US43.8 billion) and Baker & McKenzie ($42.7 billion). Freehills and Allens rounded out the top five, ahead of international firms including Allen & Overy, Norton Rose and Latham & Watkins.

Mallesons' number one placing in the Bloomberg analysis was a big improvement on the firm's 2009 ranking of 11th.

Clayton Utz jumped from 2009's ranking of 30 to second place in 2010, replacing Bakers. Other big improvers included Allen & Overy, which went from 47^th place in 2009 to sixth in 2010 and Norton Rose, which jumped from 31^st to eighth.

In terms of total number of deals, Indian firm AZB & Partners topped the list, advising on 108 deals. In second place was Bakers (92 deals), with South Korea's Kim & Chang, Singapore's WongPartnership and Minter Ellison rounding out the top five.

To round out a good 2010 for Mallesons, the firm also topped the Dealogic M&A Legal Adviser League Table for announced and completed M&A deals. Mallesons had a market share of 39.2 per cent of announced deals by value, putting it just ahead of Freehills (38 per cent) and Clayton Utz (28 per cent).

Maslen-Stannage said that her firm, Freehills, takes note of all the surveys, and doesn't rank one over another. However, she said that given that M&A is a "core part of the business", the number of deals is monitored the most closely.