WMI, the British arm of the American Waste Management company, will build a waste treatment and recycling plant and run rubbish collection and street cleaning services.
The 10-year contract has been awarded to WMI's Spanish division, Ingenieria Urbana, by the city council of Murcia.
Ingenieria Urbana has been providing Murcia with similar services for more than two years.
WMI was floated on the Stock Exchange through a listing of 20 per cent of its shares in April 1992 and soon gained a reputation as an acquisitive company.
It runs a joint-venture waste business with Wessex Water, and earlier this year WMI subscribed to the privatised water company's rights issues.
Under the arrangements for the cash call WMI's stake in Wessex could rise to 23 per cent in 1995, but many believe its intentions are eventually to control the company.