A 17th-century painting by El Greco brought an artist auction record of £9.15 million at Sotheby's Old Masters sale in London last week.

St Dominic In Prayer, by the Spanish master, was offered on the market for the first time (est: £3.5-5m).

Another oil painting by El Greco, titled Christ on the Cross, fetched £3.4m.

A record for a female Old Master at auction was set with a work by Dutch still life painter Rachel Ruysch, bringing £1.65m.

Clients from 33 countries participated in the sale with a record number of registered bidders from Asia and the Middle East. A Russian telephone bidder reportedly prevailed for the El Greco.

"We’re now firmly in a new era, where clients from new markets are collecting Old Masters in new ways. Our response has been to offer the most exciting and diverse works we can find – and to present them in a more contemporary way,” said Alex Bell, Worldwide Head of Sotheby’s Old Master Paintings.

More than 40% of the lots sold went above their lower estimates. New auction records were set for eight artists, including Claude-Joseph Vernet and Giandomenico Tiepolo.

The £35m sale generated more than £12m for UNICEF from El Greco's St Dominic in Prayer, the Tiepolo and another work by Corneille de Lyon, lots that came from the private collection of the late German industrialist Gustav Rau. He donated the paintings to UNICEF in 2001.