An ability to "reinvent yourself" should provide lawyers with the option of pursuing alternative careers, according to a former lawyer who has scaled the heights of private practice, corporate counsel, investment banking, and been at the centre of a political storm.

That's the view of John O'Sullivan, who addressed the ACLA Conference on the topic of career pathways of an in-house lawyer.

O'Sullivan did not renew his practising certificate when he took his current role as the chairman of the Investment Banking Department with Credit Suisse Australia in 2008. Prior to that, O'Sullivan was a partner for 20 years with Freehills between 1983 and 2003, leaving to take the role as general counsel with the Commonwealth Bank. He says that by "being strategic" with his career, he was able to move from private practice to the corporate sector, and then eventually leave the law altogether.

"I have been lucky to work across a lot of different industries and across a lot of different skills," he said. "And the one thing that good lawyers should be able to do is to reinvent themselves and to do new things and pick up new skills.

"If you push yourselves, you will be amazed at the opportunities that will open up to you."

O'Sullivan has also been heavily involved in politics. He has been a long-time supporter and donor to Malcolm Turnbull, and in November last year, when Turnbull was Opposition Leader, he became embroiled in the Godwin Grech affair.

It was revealed that Grech, a Treasury Official, had emailed O'Sullivan with advanced details of the financial services advisory panel relating to the OzCar scheme. Credit Suisse was later selected to manage the scheme, with Grech and O'Sullivan continuing to exchange emails while Grech was a Treasury Official.

Grech stood down after it was revealed he had forged an email from a Rudd staffer.

In speaking at the ACLA Conference, O'Sullivan said that while some private practice lawyers "should never leave the law", those with both technical acumen and the right management and people skills were well positioned to ensure the switch to an in-house role was a successful one.

"There is a hard core of technical excellence that you have to have," he said. "You have to have a general counsel that is familiar with the Corporations Act, the listing rules, continuous disclosure and the sort of things that are critical to give advice in an ASX-listed company."

After admitting that it took him 25 years to become strategic with his career, a career that included acting for clients such as the Commonwealth Bank, Telstra, St George Bank, Air New Zealand and CSR, O'Sullivan has changed tack twice in a little over five years.

He moved on from Freehills in 2003 ("transactional work has a limited span," he commented) and moved to the CBA. O'Sullivan said it wasn't just leaving the "ivory tower" of his Freehills office high up in the MLC Centre for the less salubrious surroundings of an office above Wynyard Station that was different about leaving private practice.

"Life in private practice is essentially transactional," he said. "The kind of work that you do is frequently one off transactional work for clients you may see once or twice a year, while in-house, you are seeing the same clients doing the same kind of work.

"That kind of relationship legal work is very rewarding because you get close to the business, but for adrenalin junkies, like M&A lawyers typically are, it can be a bit of a shock. You could get relevance deprivation syndrome because you are not on the front page of Lawyers Weekly any more."

O'Sullivan said learning your different role within an organisation when moving in-house, and the attitude and perception of the role of general counsel also takes some getting used to.

"You have to come to terms with the fact that you are now a cost centre, not a profit centre. That can be a bit traumatic for the high-flying M&A lawyer ... You are constantly feeling the need to demonstrate that you are providing value for money. I know that is a constant challenge for in-house lawyers."

Despite the challenges of coping with the change in perceptions and expectations from senior management that go with a new role, O'Sullivan believes that in-house roles provide lawyers with valuable skills.

"In-house lawyers acquire some terrific skills that you don't acquire in private practice," O'Sullivan said. "In-house lawyers, whether they realise it or not, soak up by osmosis the commerce of the business. You learn a bit about numbers, a bit about accounting and a lot about how business organisations run.

"You do learn real commercial skills. In private practice, you are an observer, rather than somebody directly experiencing the need for those skills."