UPDATE 2-Chemspec ADRs edge up in debut

(Adds background on company and updates price)

NEW YORK, June 24 (Reuters) - Chemspec International Ltd (CPC.N) shares edged up in their debut trading session on Wednesday following the Chinese specialty chemicals maker's initial public offering.

Chemspec ADRs started trading at $9.45, at a 5 percent premium, and later were up 1.8 percent at $9.16 on the New York Stock Exchange.

Chemspec, which primarily serves electronics and pharmaceutical manufacturers, raised $72.7 million in its IPO Tuesday night after the deal priced at $9 per American Depositary Receipt, at the top of its estimated range.

Chemspec, which sold 8.08 million ADRs, was the eighth company to go public on a U.S. exchange in 2009.

Chemspec was founded in 1996 and said in its prospectus that customers include Eli Lilly & Co (LLY.N) and Merck KGaA (MRCG.DE).

Chemspec warned that it is vulnerable to the costs of raw materials used in its products, such as fluorine and hydrofluoric acid, which accounted for 81 percent of the cost of its sales last year.

In a recent filing, the company said it was the largest manufacturer of fluorinated specialty chemicals in China with a market share there of approximately 25 percent in 2008, and global sales of $138.3 million that year.

The company plans to use about $45 million of IPO's proceeds for the expansion of its manufacturing capacity.

Chemspec's IPO was underwritten by Credit Suisse (CSGN.VX) and Citigroup (C.N). (Reporting by Phil Wahba; Editing by Lisa Von Ahn and Gerald E. McCormick)