Norton Rose Fulbright has made no secret of its desire to build up in New York, and yesterday's (2 February) news of its merger talks with Chadbourne & Parke could potentially give the global giant the Manhattan bulk it seeks.

The proposed deal – which was confirmed by the firms last night – would add nearly $250m (£200m) to Norton Rose's revenue, bringing it close to the $2bn (£1.6bn) mark.

Crucially, it would also add more than 60 partners in New York and take global lawyer headcount to roughly 4,000, with the combined firm having particular strengths in energy, project finance and disputes. Outside of the Big Apple, Chadbourne also has bases in Washington DC, Los Angeles, Mexico City, Moscow, Istanbul, Dubai, Johannesburg, Sao Paulo and London.

But what do partners think of the prospective union, which comes after repeated attempts by Chadbourne to find a merger partner against a backdrop of falling revenue and headcount in recent years?

Sources close to Chadbourne say the firm has approached a number of firms about a tie-up during the past year, including Baker McKenzie, DLA Piper and Hogan Lovells.

Many can see the sense of the latest prospective deal. A senior partner at one UK firm comments: "One can see clear synergies, particularly in areas like energy. The deal would strengthen the Norton Rose Fulbright offering in New York by providing Chadbourne's insolvency capability and project finance capability."

They're a great firm in projects – I know them and I like them

Another adds: "I think it's quite a good move for both firms. Mergers are clearly part of the strategy and I think there's a good project finance alignment between each firm. Chadbourne has been looking at opportunities for a while and the firm will get joined-up global coverage from this."

Inside Norton Rose, multiple partners said they had not been briefed on the deal. Despite this, one partner says he is optimistic about it: "They're a great firm in projects. I know them in Moscow and I like them."

While Norton Rose pulled off its transatlantic deal with Houston's Fulbright & Jaworski in 2013, through which it gained 11 offices and some 800 lawyers in the US, the perception has remained that the Texan firm did not provide the New York firepower crucial for true global success.

The senior partner comments: "Fulbright gave them a US platform but I think Chadbourne is a better fit."

Another City partner at a rival firm adds: "In New York, the substantial Chadbourne team would be the dominant presence and in that respect they will have a very important role in the network."

For Chadbourne, the consensus is the firm has little option but merging, in the wake of a string of partner exits in the past few years, including the loss of a six-partner product liability group to legacy Herbert Smith in New York in 2012, which brought across trophy client British American Tobacco.

It has also seen departures in the past year, including corporate and project finance partner Margarita Oliva Sainz de Aja, who joined Baker McKenzie last month; a three-partner arbitration team who joined Cooley last December; and bankruptcy partner Douglas Deutsch, who joined Clifford Chance last summer.

They took Watson Farley very far down the line and then they completely changed the terms of the deal at the last minute

One former Chadbourne partner says: "They have shrunk and shrunk and have not been able to maintain any critical mass in any group. They just can't seem to keep people together and can't keep the stars there.

"It is sad because it is the end of Chadbourne's identity – it would have been better to have merged earlier when it could have preserved its culture, because it is going to be dwarfed by Norton Rose Fulbright."

A senior management figure at a global law firm remarks that Chadbourne is "a very good firm that is simply too small for its geography". He adds: "It's an old-fashioned model that many very good firms stick to. Their offices aren't large enough to benefit from cross-regional referrals. It has been in the market for a merger for a while."

However, some warn that Norton Rose Fulbright should be careful in its dealings with Chadbourne, which previously held aborted merger talks with UK firm Watson Farley & Williams in 2007 and Pillsbury in 2015.

Another ex-Chadbourne partner warns: "Norton Rose need to do their due diligence on Chadbourne. They took Watson Farley very far down the line and then they completely changed the terms of the deal at the last minute – a very New York approach to a merger."

The former partner adds: "I would want to ask Peter Martyr: 'Do you really know who you are getting into bed with?'"

Meanwhile, Norton Rose has historically struggled to turn the huge revenue growth that has come via its mergers into bottom-line gains. The firm does not provide a global profit per equity partner figure, but estimates from Legal Week's US sister title suggest a figure of £392,000 for the 2015 financial year, up 3.5%.

Chadbourne is a very good firm that is simply too small for its geography. It has been in the market for a merger for a while

A senior partner a UK firm questions: "Norton Rose doesn't seem to have had a hugely beneficial financial performance from other mergers. When are they going to stop investing and see a return? What are they going to get out of this?"

Legacy UK firm Norton Rose has been through a succession of major international combinations. It combined with Australian firm Deacons in 2010, then in 2011 with Canadian firm Ogilvy Renault and leading South African firm Deneys Reitz. These were followed by a second Canadian merger with Calgary's Macleod Dixon in 2012, ahead of the 2013 Fulbright union. More recently, the firm inked a deal with Vancouver firm Bull Housser & Tupper last year.

According to one partner who spoke to Legal Week sister title The American Lawyer, the Chadbourne deal could be voted on within weeks, after discussions started around summer 2016.

The partner said some of Chadbourne's overseas offices might be a part of the US LLP of Norton Rose Fulbright, while other overseas offices may belong to other parts of the Swiss verein firm.

Despite the uncertainties surrounding the deal, the overall consensus is Norton Rose has found a strong match in Chadbourne, with its New York headquarters and high quality project finance and reinsurance groups.

As one London partner concludes: "It seems to be a good move if you take a 10-year view. I take my hat off to them. You have to credit them – they did a few mergers quite quickly at the beginning. Now they are being quite measured."

Additional reporting by Christine Simmons. For more, see Norton Rose Fulbright, Chadbourne Chase Merger as Project Pipeline Thaws.