Robertson Group has continued its recovery from the property downturn by increasing employment and paying down all its debt as it moves into a new phase of investment.

The £73 million deal to sell 21 infrastructure investments to Dalmore Capital has enabled the Elgin-based group to repay all its £61m of debt and emerge with £12m in cash, according to its 2013 accounts just posted at Companies House.

Robertson plans to reinvest in larger infrastructure projects and continue its diversification into project management and consultancy for the public sector.

The chairman's report by 75% owner Bill Robertson says the group has a record order book of £1.5 billion, and is halfway through a five-year strategic plan with a key focus on enhancing trading margins across the group. Gross margins fell slightly in the year to 31 March 2013, from 8.5% to 8.3%, on turnover in core activities down 7.4% to £210m.

The previous year's £1.1m pre-tax profit slid to a £1.1m loss, while the group says net earnings fell from £6.5m to £3.5m. But last year's £19m bill for finance charges is likely to be wiped out this year after repayment of bank debt, which had risen from £50m to £61m at the last year end.

Mr Robertson says the group has "ambitious plans which will benefit from this new injection of cash to invest for the future". The rise in debt in 2012-13 was partly due to £7m of new Private Finance Initiative investments.

He says the group is also maximising its housebuilding and property development skills for social housing and regeneration opportunities. Its Urban Union joint venture company is delivering a significant project in Laurieston, Glasgow and has recently secured preferred partner status for a project in Pennywell, Edinburgh, for 300 social homes and 300 private units.

Robertson Construction has been "very successful in the North of Scotland", the chairman writes, building for the whisky, food, fish farming and energy sectors, and had added an in-house civil engineering and building services operation to enhance margins.

It was one of only two contractors to retain its position on the NHS Scotland 2 framework and is also involved in the East Central Hub public sector framework, where Robertson Capital Projects was critical to the success of the Amber Blue consortium. The hub has identified £350m of projects which could benefit Robertson's investment, construction and facilities management services.

The FM arm enjoyed turnover and profit growth last year and is a "core part of the group's growth strategy", Mr Robertson says.

Robertson Homes built 17% more units, but took a £5m writedown on the value of its landbank. Employment across the group grew from 1064 to 1132 last year. It recruited 41 new apprentices or trainees and provided 233 weeks of work placement. Remuneration of the top-paid director, thought to be Mr Robertson, rose from £412,000 to £591,000.

The chairman says he is "delighted" with the achievements "against the backdrop of a prolonged and difficult banking and economic environment".