UPDATE: Sen Mikulski: May Subpoena Dispersant-Maker Nalco

(Updates with Nalco spokesman saying company wasn't asked to testify) By Siobhan Hughes Of DOW JONES NEWSWIRES WASHINGTON (Dow Jones)--Sen. Barbara Mikulski (D, Md.), said Thursday she might subpoena Nalco Holding Co. (NLC) executives to testify at a hearing because the maker of a dispersant being used to combat a Gulf of Mexico oil spill declined to testify at a hearing. "I'm sorry they didn't come," she said at the start of a Senate Appropriations subcommittee hearing. "We're not going to subpoena them for this hearing; we might subpoena them for another hearing." A Nalco spokesman said the company wasn't asked to testify and that one of the trade associations that Nalco is a member of was asked to testify. BP PLC (BP, BP.LN) has been using Nalco's Corexit 9500 product to break up oil that has been leaking from an undersea well. -By Siobhan Hughes, Dow Jones Newswires; (202) 862-6654; siobhan.hughes@dowjones.com (END) Dow Jones Newswires July 15, 2010 16:11 ET (20:11 GMT)