Stewart also revealed that Telling had been battling a cancer-related illness for two-and-a-half years before retiring as a non-executive director just weeks before he died.
He said: "Towards the end of David's disease, he realised that it was terminal and so he strengthened the board with new directors."
These directors included the Bristol-based businessman David Ord, who came in as chairman.
Stewart was speaking after the group's results for the half-year to 30 September. In the interims, pre-tax profit was up 14% on the same period last year to £18m, and turnover rose by the same percentage to £316m.
Stewart said that the results were encouraging in comparison with the sector as a whole.
He added: "This is a strong performance for the support services sector. We're pretty pleased with the results."
The group has made several acquisitions in recent months, including Eagle Pest Control and Trident Safeguards. Stewart said the group was unlikely to be on the lookout for further bolt-ons in the coming year.
He added: "I think it would be sensible to settle down the three that we acquired recently."
Mitie expects to be boosted over the next year by its work with Japanese construction group Kajima. Stewart said: "We have picked up six facilities management contracts with Kajima. We have been very successful at developing PFI schools with them."
The group also announced a dividend of 1.1p a share, up 38% on the same period last year, and has a cash balance of £38m, down from £50m last year, because of the acquisitions.
Capita said it was working on further bids worth £2.4bn. In two of these it is in sole discussions with the client, and if these end successfully it will add £70m of revenue in 2004.