President Julio Cesar Turbay Ayala has decided he would not begin serious negotiations with the M-1. guerrillas before Sunday's elections, well-informed sources said today.

Today's scheduled talks with the guerrillas, who are holding an estimated 35 hostages in the Dominican Republic Embassy here, were postponed until Wednesday. The move suggested there is no quick end to the crisis, now in its seventh day.

Turbay is said to fear that a quick resolution of the crisis may prompt other guerrilla groups to disrupt Sunday's elections for municipal councils and state legislators.

Moreover, the president is reported to believe that an end to the embassy siege would not benefit the Liberal Party, which he heads.

Sources close to Turbay said that his initial decision, after the embassy was seized last Wednesday, was to hold firm and not release even one of the prisoners demanded by the M-19 guerrillas in exchange for the safe release of the hostages.

It is generally believed that the Colombian military, which has charge of national security, is continuing to resists a deal in which at least some of the prisoners would be released in exchange for the hostages. Among the hostages are 13 ambassadors, including Diego Asencio of the United States.

While the general feeling among well informed observers here was that the situation will remain unchanged until next week at the earliest, there were reports today that the guerrillas have promised to release all of the remaining Colombian hostages, possibly Wednesday. That would leave the 13 ambassadors and a number of less ranking diplomats from other countries and at least two Colombian Foreign Ministry officials who would not be included in among those who may be released.

There were also reports from excellent sources today that several of the ambassadors held inside the embassy had been in contact with their wives within the past 24 hours asking them to prepare their passports. No one could be sure, however, what significance these requests might have.