Carlos Salinas de Gortari, Mexico's ruling party presidential candidate, took a narrow early lead Thursday in a tight race over his leftist challenger in the first unofficial results divulged by a member of the Federal Electoral Commission.

The election Wednesday has been marred by opposition claims of massive fraud by the ruling Institutional Revolutionary Party, or PRI, and delays in vote tallies because of computer breakdowns at the Electoral Commission - the non-partisan board overseeing election results.Salinas de Gortari, who holds a Ph.D. from Harvard in political economics, received 96,379 votes from 2,000 voting stations out of the 55,000 nationwide, according to Fernando Elias Calles in an interview with United Press International.

Elias Calles, assistant interior minister and technical director of the Federal Electoral Commission, stressed the returns from stations across the country - the first hard numbers divulged - were unofficial. Final official results were not expected until Sunday.

The four-party National Democratic Front coalition supporting Cuauhtemoc Cardenas, the former PRI governor who went into the opposition, had tallied a total of 80,680 votes, Elias Calles said.

Manuel Clouthier of the rightist National Action Party, or PAN, garnered 37,742 votes. Traditionally, the PAN had been Mexico's largest opposition party.

Gumersindo Magana of the centrist Mexican Democratic Party, or PDM, pulled in 22,235 votes, while Rosario Ibarra of the far-left Revolutionary Worker's Party got 1,667 votes.

Never has a PRI presidential candidate ever been in an electoral vote-count where his victory has been in doubt.

Earlier, PRI Chairman Jorge de la Vega Dominguez claimed a solid victory for Salinas de Gortari but released no figures.

The PRI had its own sophisticated computer network across Mexico that was supposed to give out streams of electoral data beginning shortly after the polls closed Wednesday evening but it never occurred.

"At this time even in the most remote parts of the country we are receiving information from party delegates and representatives that confirms our conclusive, legal and indisputable victory," de la Vega Dominguez said.

"We confirm that the Mexican people in an atmosphere of liberty and democracy voted in favor of the Mexican who will guide the nation in the next six years, Mexico won, Mexico gave the victory to Carlos Salinas de Gortari," de la Vega said.

Cardenas accused the ruling PRI of "planning massive fraud" in Wednesday's presidential and legislative elections.

Cardenas, together with Clouthier, met at the Interior Ministry with the Federal Electoral Commission and said they would reject the results because of "a series of electoral irregularities throughout the day,"

The first preliminary results, expected before midnight Wednesday, were delayed because of a failure in the Federal Electoral Commission's computer system.

The failure, according to Porfirio Munoz Ledo, leading FDN candidate for the senate, was part of the PRI's alleged campaign of fraud.

"The PRI never thought they would be losing in such a way," Munoz Ledo said.

Pre-election polls showed that Salinas, 40, would be elected but with the lowest percentage ever of any PRI candidate.

"Salinas was losing in 12 states and lying third in the capital . . . and when the unfavorable results began to come in they suspended the computer sytem," Munoz Ledo said.