Gains said Mowlem had spent £8.2m on PFI projects during the six months to 30 June, of which £2.5m went on bid costs. The group spent about the same on bids last year.
Gains said the main problem was the time it took to close the deals.
He made his comments as the group posted strong interim results, with pre-tax profit up 30% to £11.8m for the six months to 30 June, compared with the same period last year. Turnover increased 26% from £664m to £836m.
The company attributes its performance to a strong order book. This was worth £1.8bn, up 36% on the same period last year. In its statement, the company said it was aiming to grow through acquisitions, expansion in its existing markets and the development of PFI contracts.
Gains added that the group would continue to make strategic acquisitions but not in the construction sector.
He said: "We are looking to increase work in support services through acquisition, but acquisition in construction is not on the agenda, unless in niche areas."
Gains would not reveal which niche areas he was considering, but said the acquisitions would complement the sectors group's portfolio in sectors such as water and rail.
In July, Mowlem bought cleaning company Pall Mall Holdings for £42.3m, bringing £188m of forward orders to the group.
Pall Mall is the fourth largest cleaning company in the UK and is a vital step in Mowlem's transformation into a construction and services group.
The results revealed that Mowlem's Skillbase initiative, which involves carrying out repair work for householders on behalf of insurance firms, broke even in the six-month period after it was merged into services arm Aqumen.
Gains said the initiative was likely to report a small profit at the end of the year, with the figure increasing in 2002.
Mowlem comprises separate facilities management, environmental services, construction, and investment companies.
With the results, the company announced a dividend of 2.5p, compared with 2.25p at the end of 2000.
