SINGAPORE (Reuters) - Singaporean property tycoon Ong Beng Seng is cooperating with the city-state's anti-graft agency in a case launched earlier this week involving the transport minister, Ong's company said on Friday.

"No charges have been filed against Mr Ong," the company Hotel Properties Ltd said in a statement, adding that Ong has been given a notice of arrest and posted bail of S$100,000 ($75,843.76).

The company added that Ong was asked by the Corrupt Practices Investigation Bureau (CPIB) to provide information on his interactions with transport minister S Iswaran.

Contacted by Reuters the CPIB said it had no immediate comment on the issue.

Shares in Hotel Properties were down 4.4% on the news.

The case, about which the CPIB has provided few details, is a rare high-level probe in a country that prides itself on a government free from corruption.

Prime Minister Lee Hsien Loong on Wednesday said he had instructed Iswaran to take leave of absence until the investigations were completed.

($1 = 1.3185 Singapore dollars)

(Reporting by Reuters staff; Writing by Kanupriya Kapoor; Editing by Martin Petty)