Mr Lewis, who will complete a two-year secondment to Buckingham Palace in September, is being groomed by Centrica chief executive Roy Gardner for a key role at either the newly acquired AA or the expanding Goldfish financial services arm.
Mr Lewis, who has been credited with presiding over a subtle improvement in the Royal Family's public image since his arrival in September 1998 after a febrile period for the monarchy, would not comment on his future yesterday.
But he is known to be keen to return to the business world after "a fascinating and very different time at Buckingham Palace, but in a job that by its nature should be done only on a short-term basis".
A Centrica insider added: "Roy Gardner is a great fan of Simon's and has told him that there will be a substantial business for him to run on his return rather than returning to the public affairs arena.'
Mr Lewis, who is also known to have impressed Tony Blair, is expected to be given one of two jobs as Centrica prepares to assimilate the AA into its existing businesses and build on its huge customer base of 9.5 million motorists.
One option for the career public relations expert - whose experience has included working for the Social Democrats, SG Warburg and NatWest - is building up the AA's publishing and traffic information side and melding it together with Goldfish's successful shopping guides.
The AA already publishes a range of travel guide books, a members' handbook and its members' magazine, a business which Centrica believes will dovetail well with the Goldfish consumer guides on buying expensive products such as cars, computers, domestic appliances, home entertainments and financial services.
These guides - 19 in total - are already offered to the million holders of its Goldfish credit card and are likely to be expanded further.
The other option for Mr Lewis would be to build up Centrica's financial services activities, again melding Goldfish's business in this area - such as its credit-card and home insurance services - with the range of financial services offered by the AA.