Oman-based Renaissance Services, one of the top ten offshore vessel operators in the world, tumbled on fears a subsidiary's $500 million London listing may be delayed, weighing on Oman's index.

The country's index slipped 0.5 per cent to 6,339 points, a 12-day low.

Renaissance fell 6.6 per cent, with the company holding an analysts' get-together after Monday's annual meeting.

Dubai-based unit Topaz's offering was expected to give it a market capitalisation of about $1.7 billion.

'During the meeting, the management indicated it will delay the IPO until it receives the implied valuation of $1.5 billion,' investment bank EFG-Hermes wrote in a research note.

'There was a statement from the CEO that the IPO can be deferred till starting next year if the recent events in the Middle East affect the valuation of Topaz.'

The stock had risen as much as 5.2 per cent after the IPO announcement earlier this month, but has now given back these gains.

'If the Topaz IPO goes through, we will see a strong comeback for the Oman market,' says Adel Nasr, United Securities brokerage manager.-Reuters