Field Fisher Waterhouse and Osborne Clarke (OC) are in early-stage talks about a potential combination that could create a merged firm with revenues of nearly £200m, Legal Week can reveal.

News of the discussions, have been going on for around two months, comes weeks after Field Fisher's merger talks with LG were called off in June.

Discussions have so far been limited to senior partners at both firms and it is understood they were not planning to release details to the wider partnerships for several months to come.

If the union goes ahead, the tie-up would create a UK top 20 firm with combined revenues of around £195m, based on the two outfits' 2011-12 results.

The firms also posted similar profits per equity partner (PEP) figures last year, with OC coming in at £406,000, while Field Fisher partners took home an average of £410,000 following a drop of nearly 20%.

Separately, it has emerged that Field Fisher managing partner Matthew Lohn has been signed off sick from the firm since the talks with LG ended, with technology and outsourcing head Michael Chissick filling in on an interim basis.

Lohn was elected as managing partner in October last year following a contested vote that also saw Chissick put himself forward.

It is understood that Mark Abell, the chairman of the firm's European franchising network and a senior partner within the firm, is also playing a leading role in the OC talks.

In a statement, Field Fisher said: "It is well known that merger is on Field Fisher Waterhouse's agenda as potentially one way of achieving our ambitious growth plans and strategic objectives. This means that like many in the mid-market we have been speaking to a number of firms to explore the benefits that such a merger would bring.

"We will not be commenting on individual talks unless they reach an appropriate stage."

Separately, Field Fisher chief operating officer Charlie Keeling, who was appointed to the role in November last year, is leaving the firm to join Clyde & Co.

Field Fisher has offices in London, Brussels, Duesseldorf, Hamburg, Manchester, Munich, Paris and a recently launched base in Palo Alto, while OC, which also has a Silicon Valley office, has a presence in Bristol, London and Reading, as well as offices across Germany, Italy and Spain.

Following the end of discussions with LG, Field Fisher has taken steps to reorganise its business, overhauling its sector groups in August this year, with the firm no longer listing public sector work among its core areas of focus and cutting back its sectors from 11 to five.

In a statement, OC said: "We're committed to an expansion plan, so we always evaluate opportunities as they arise. Any potential merger partner would have to be a great cultural and strategic fit with OC.

"We don't comment on any talks until they're at an appropriate stage."

One ex-Field Fisher partner said: "The firm has been talking about merging for a while because the partnership felt it wanted the firm to get bigger.

"What's interesting about this is that the firm has always said that it would want to be the dominant partner in a merger and I think, while it would fit well with OC in terms of sectors and footprint, they are fairly equally weighted firms with no obvious leader."