BY JUAN O. TAMAYO

 BOGOTA, Colombia -- Reviving Colombia's flagging hopes for peace, President
 Andrés Pastrana and the leader of the country's largest guerrilla force agreed
 Friday to reopen their long-fruitless negotiations and add third-party monitors to
 expedite the search for a lasting truce.

 ``I believe that today we have resuscitated the peace process,'' Pastrana declared
 in a news conference as he patted the arm of Manuel ``Sure Shot'' Marulanda,
 head of the 17,000-member Revolutionary Armed Forces of Colombia, known as
 FARC.

 The pact signed by Pastrana and Marulanda after a two-day summit in a
 rebel-controlled region of southern Colombia made only ambiguous references to
 steps designed to end a bloody conflict that has caused alarm among Colombia's
 neighbors and in Washington.

 Still, it eased growing fears of even worse violence, voiding Pastrana's recent
 threats to end the existence of the sanctuary he ceded to Marulanda's rebels in
 1998 unless they agreed to restart the peace talks they froze on Nov. 14.

 Pastrana later extended the life of the demilitarized zone used by the rebels for
 eight months, the longest of the many extensions he has issued since 1998.
 Marulanda, 70, was far less effusive than Pastrana, largely deferring to the
 president's answers. Asked about future progress on key issues, he shrugged
 and said, ``Some day the president will say if they are good or not.''

 WHAT WAS AGREED

 The 13-point Pact of Los Pozos, named after the hamlet 200 miles south of
 Bogotá where the talks were held, agreed to end the freeze on talks imposed by
 the FARC to demand a government crackdown on right-wing paramilitary squads
 recently pushing the rebels out of some of their traditional redoubts.

 It also promised to ``expedite'' negotiations on an exchange of sick prisoners,
 about 50 from each side, and a later unilateral FARC release of another 100 of the
 500 soldiers and policemen they hold.

 Negotiators will also begin discussing a cease-fire when they resume meeting
 Wednesday, the pact said, an issue that the FARC had long insisted on
 postponing until more progress has been made on other fronts.

 ``This is something very promising, an apparent change in the FARC's position
 that peace has to be negotiated in the middle of war,'' said former foreign minister
 Rodrigo Pardo.
 THREE NEW PANELS

 The agreement also created three panels to advise negotiators on issues that
 have repeatedly stalled the peace talks since they were launched in 1998
 following the creation of the 16,200-square-mile demilitarized zone in the southern
 states of Meta and Caquetá.

 One will make recommendations on the growing problem of the paramilitaries and
 ``lessening the intensity of the conflict,'' which Pastrana said included the FARC's
 practice of kidnappings-for-ransom.

 A second panel will take up any side issues that threaten the main talks -- such
 as a FARC rebel's hijacking of a commercial plane last year -- and the last will
 ``periodically evaluate and report on'' conditions in the DMZ.

 Pastrana's popularity has plummeted amid growing complaints that the FARC is
 stalling at the negotiations, which have produced little progress since 1998, while
 using the DMZ to hide kidnap victims, train fighters and launch hit-and-run raids
 against surrounding towns.

 ALLAYING FEARS

 ``We know there are people who are skeptical of the process. That's why we
 invited outside people to come and check for themselves,'' Pastrana said.

 The pact said the two-day summit ``identified achievements and weaknesses'' in
 the peace process but insisted that it had ``generated solid foundations on which
 the search for national reconciliation should continue.''

 But it offered ambiguous language on some of the more contentious issues,
 signaling that the two sides remained at odds but willing to continue discussing
 them later.

 While Marulanda insisted before the summit that he wanted to discuss Plan
 Colombia, Pastrana's plan for a counter-narcotics offensive backed by $1.3 billion
 in largely military U.S. aid, the agreement made only indirect reference to the
 controversial program.

 The FARC views the U.S. aid as a thinly-disguised attempt to cut them off from
 the hundreds of millions of dollars they earn each year by ``taxing'' Colombia's
 cocaine and heroin traffickers.

 Nevertheless, the pact said the rebels ``do not oppose projects for the manual
 eradication and substitution of illegal crops'' and agree with the government on the
 need to preserve the environment.

 Asked if that would mean a change in Plan Colombia's heavy emphasis on aerial
 spraying of herbicides against coca and opium poppy fields, Pastrana referred
 only to forests cut down by farmers to plant illegal crops.

 PASTRANA OPTIMISTIC

 Despite the agreement's overall tone of leaving significant issues for later
 discussion, Pastrana pronounced himself cheered by his round of conversations
 with Marulanda, their third since 1998 but first in two years.

 ``If there was something important about this meeting it is that we talked about all
 the themes that we had to discuss,'' he said. ``We talked about where we made
 progress, where we didn't make progress. They were two days of much
 usefulness.''