UPDATE 1-Thailand's Siam Cement puts chemical unit's IPO on hold

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Siam Cement says IPO may not appropriate at this time

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Company to proceed with IPO after conditions improve

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Shares of Siam Cement have dropped 7% year to date

(Adds details of the IPO, context of Thailand and companies' information in paragraphs 3 to 9)

SINGAPORE, Aug 28 (Reuters) - Thailand's largest industrial conglomerate Siam Cement said on Monday it has decided not to proceed with the domestic initial public offering (IPO) of its unit SCG Chemicals due to unfavorable market conditions.

Siam Cement said in a stock exchange filing that "it may not be appropriate to proceed with the IPO at this time".

The company, which counts King Maha Vajiralongkorn as its largest shareholder, attributed the decision to "the readiness of both Thai and foreign capital market investors to take on a sizeable IPO of a Thai company at this time as well as external circumstances such as the economic situation and energy crisis."

Siam Cement announced in April last year the IPO plan for SCG Chemicals. It said in Monday's statement the IPO approval period was extended until Oct. 4 this year but cannot be further extended.

Siam Cement said it intends to proceed with SCG's IPO "in due course" after conditions have improved.

Thailand, Southeast Asia's second-largest economy, last week chose its new prime minister, real estate tycoon Srettha Thavisin, after months of a caretaker administration and political limbo following a May general election.

Siam Cement's decision on SCG's IPO could weigh on other potential listings on the Thai stock exchange. Other Thai companies seeking IPOs include Big C Supercenter and CPF Global Food Solution.

Siam Cement, whose businesses range from packaging to investments, have seen its shares drop 7% this year. It has a market value of $10.9 billion, according to Refinitiv data.

SCG is Siam Cement's chemical arm, which produces plastic resins or polymers moulded into products used for food packaging to automotive parts, according to its website. (Reporting by Yantoultra Ngui; Editing by Muralikumar Anantharaman)