Deep Marwaha, 35, born in London to Indian parents, made the remark in an "abuse-filled" message sent to 34-year-old colleague Khalid Shafique while both were working in Saudi Arabia, The Sun reported.
The message allegedly ended with a taunt: "Now show what you can do. I know lots of sheiks."
Shafique, also a British citizen, told police he received the message after quitting British conference-organising firm Informa.
Both men live in Dubai but regularly worked in Saudi Arabia.
Marwaha, however, said he was asleep when the text message was sent.
A Dubai court has adjourned the case till September.