A group of seven U.S. lawmakers has urged the government to consider blocking a plan by a subsidiary of Nippon Telegraph and Telephone Corp. to acquire a U.S. Internet company, according to their letter to U.S. Trade Representative Charlene Barshefsky, released Thursday.

In the letter, dated May 25, Rep. Billy Tauzin of Louisiana and six other Republican congressmen said that as long as Japan's telecom market is closed to competition, "NTT's proposed acquisition of a major U.S. Internet backbone cannot stand."

They urged the Office of the U.S. Trade Representative to join the Justice Department and the Federal Communications Commission in prying open Japan's telecom market.

"We look forward to working with you to ensure that this proposed combination will not result in a competitive disadvantage to U.S. carriers and that such combination will not result in higher prices for Internet services for U.S. consumers," the letter said.