Revenues of the 20 leading Israeli construction companies grew by 13 percent to $4.4 billion in 2006 boosted by higher investment in infrastructure projects and expansion of international activity. Economists at Dun & Bradstreet Israel, who conducted the D&B 100 ranking, found that 18 of the 20 leading construction, development and infrastructure companies generated higher revenues in 2006, partly as a result of their activities abroad. Revenue growth in the local construction sector stemmed mainly from an increase in the volume of renovations and security and defense constructions. At the same time, investments into infrastructure projects grew during the course of 2006. For another year, Housing & Construction Holding Ltd., the country's largest construction and infrastructure company owned by Shari Arison, led the D&B 100 ranking. Revenues at Housing & Construction grew by 0.5% year-on-year in 2006 to $857.1 million. Africa Israel Investments Ltd., which has the majority of its activities in the US and central and eastern Europe, was ranked in second place with $669.3m. in revenues, an increase of 6.7% over 2005. In third place came Ashtrom Group Ltd., the private construction, development and infrastructure concern, which generated $642m. in revenues last year, up 11.7% from 2005, followed by Electra Israel Ltd, where revenues jumped 28.4% in 2006 to $490.2m. Shapir Civil Engineering Ltd., which specializes in infrastructure projects, was ranked in fifth place with revenues of $267.6m. in 2006, an increase of 22.9% over the previous year. The second half of the top 10 list was headed by Heftsiba Ltd, a family-owned company, which in 2006 had the highest increase in revenue growth at 39.6% while generating $188.5m, partly due to its recent expansion of activities abroad mainly to eastern Europe. In seventh place came the U. Dori Group with revenues of $150.6m. followed by Azorim Investment in Development and Construction Ltd, which dropped to eighth place from fifth place in 2005. S.G.S. Building Company Ltd. was ranked in ninth place and A. Arenson Ltd. in tenth.