Oliver North testified Friday that when lawmakers asked about his 1985 activities for the Nicaraguan Contras, he urged his White House boss to assert executive privilege and refuse to answer.

North said he told Robert McFarlane, then President Reagan's national security adviser, that they shouldn't be answering the letters from two Democratic House members because North's work for the Contras "was not a matter for congressional intrusion."He said McFarlane rejected that argument but subsequently told him in the fall of 1985 to alter a number of memos he had written about the Contras because they contradicted the official responses McFarlane sent to Congress.

North, taking the witness stand for a second day in his 12-count felony trial stemming from actions in the Iran-Contra affair, said he initially objected to McFarlane's request, arguing there were dozens of other documents containing similar information, but a year later - in November 1986 as the Iran-Contra deal was being exposed - he followed his boss's order.

McFarlane, according to North, also ordered the destruction of certain files pertaining to secret U.S. arms sales to Iran and the diversion of profits to the Contras.

The testimony directly contradicted what McFarlane told the jury last month.

McFarlane testified that his former NSC aide never suggested the White House assert executive privilege as a response to the August 1985 letters from Democratic Reps. Lee Hamilton of Indiana and Michael Barnes of Maryland.

The letters asked about news reports that detailed North's far-flung efforts to manage a private airlift ferrying arms and supplies to the Contras at a time when Congress had banned direct U.S. aid to the rebels.

North said that when the National Security Council received the letters, he and his boss talked about a possible response and, "I recall saying we ought to invoke executive privilege."

Executive privilege means the executive branch refuses to release information to Congress based on the separation of powers provision of the Constitution.

North repeatedly stressed that he considered efforts to arm the Contras a political battle and never believed the actions he was engaged in, including the congressional correspondence, could be considered criminal.

"This was a political battle. It was a nasty political dispute. It was politics at its worse," North said. "It never occurred to me that a letter could be a violation of law. What did occur to me was that it wasn't going to be helpful."

The letters sent to Hamilton and Barnes stated all NSC staffers were "in compliance with both the spirit and the letter" of the congressional aid ban.

Those responses constitute the basis for one lying-to-Congress charge against North.

North took the stand Thursday in a surprise defense move. As a result, prosecutors said he waived his rights to protect notebooks he kept daily while he was a White House aide. (See related story on this page.)

To start the testimony Thursday, defense lawyer Brendan Sullivan said with a smile, "So. You're Colonel North."

"Yes, sir," the witness replied. "I am."

For the next two hours, North told his story to the jury that for seven weeks has heard 42 witnesses explain his arrangements for the secret 1985 and 1986 U.S. arms sales to Iran and his management of the Contra supply network.

"None of the people I worked for ever told me what we did was illegal," he said.

North is accused of 12 felony counts, including tax fraud, accepting an illegal gift and destroying official documents. If convicted on all charges, he faces up to 60 years in prison and $3 million in fines.

He has claimed all his actions in the foreign policy affair were authorized by his superiors at the White House - including former President Reagan.

North said he got his orders from McFarlane, retired Navy Rear Adm. John Poindexter, McFarlane's successor, and William Casey, the CIA director and Reagan's close friend.