UPDATE 2-China's Huawei negotiating conditions to join US hearing

* Huawei says negotiating conditions for House Intelligence hearing

* China's ZTE Corp has said it will join Sept. 13 hearing

Sept 6 (Reuters) - China's Huawei Technologies Co Ltd , the world's second-biggest telecommunications equipment maker, said it was negotiating the conditions under which it would agree to take part in a U.S. congressional hearing into alleged security threats posed by Chinese telecommunications companies.

The House of Representatives Intelligence Committee announced earlier on Thursday that it would hold an open hearing on Sept. 13 as part of its investigation into "the national security threats posed by Chinese telecommunications companies working in the United States."

Huawei has received the committee's invitation to testify next week, "and will appear at the hearing if the appropriate arrangements are agreed with the committee," William Plummer, a company spokesman in Washington, said in a statement.

He said in a telephone interview that the arrangements were still under negotiation with the committee but declined to elaborate.

Plummer said Huawei looked forward to further contributing to a better understanding by panel members of the "globalized and interdependent" communications technology industry.

Huawei also called attention to the work it said it is doing to promote "universal and industry-wide security assurance solutions."

"The integrity of Huawei's operations and performance and the quality and security of our products are world-proven, across 140 markets," Plummer said.

The House Intelligence Committee's hearing is part of an investigation of the two biggest Chinese telecommunications companies doing business in the United States, Huawei and ZTE Corp.

The committee is reviewing "the extent to which these companies have ties to the Chinese government or otherwise provide the Chinese government an opportunity for greater foreign espionage, threaten our critical infrastructure, or increase the opportunities for Chinese economic espionage," the committee said in a statement on Thursday.

ZTE said on Aug. 29 that it would participate in the hearing.

A spokeswoman for the House Intelligence Committee did not immediately return a phone call seeking comment on any negotiations with Huawei. The committee's website did not name any witnesses for the upcoming hearing.