WASHINGTON &045;&045; The Securities and Exchange Commission will vigorously investigate Vice President Dick Cheney’s former company and take enforcement action if needed, the agency chairman said Sunday.

Harvey Pitt also said it is up to President Bush to decide whether to release documents related to the decade-old SEC investigation of his sale of stock in his former oil company. Democrats are challenging the president to do so, but a White House spokesman said ”all the relevant SEC documents” have been made public.

Lawmakers of both parties pressed again for Pitt’s resignation. They said that his previous work for big accounting firms and corporations as a private securities lawyer create too much potential for a conflict of interest.

Pitt insisted that under his leadership, the SEC has been more effective and aggressive than ever in investigating and punishing companies, executives and accountants.

He said the agency will take that stance if needed with the oil services company Cheney headed, Halliburton Co. It is under SEC scrutiny for the way it accounted for cost overruns on construction jobs during Cheney’s tenure.

Pitt stressed that he would not personally decide whether the SEC should act against Halliburton.

Normally the agency’s enforcement attorneys make such as recommendation to the SEC commissioners, including the chairman, who then vote on whether to proceed. Beside Pitt, there are currently only two commissioners &045;&045; a Republican and a Democrat &045;&045; of the full complement of five.

But House Minority Leader Dick Gephardt said Pitt should remove himself from any action whatever related to Halliburton.