Alexandria's convoluted process of selecting delegates to nominate a U.S. Senate candidate at the state Republican convention appeared yesterday to have produced a plurality of delegate votes for former Navy Secretary John Warner and an argument over who actually won the election.

The Warner campaign laid claim to 120 firm delegates out of a total of 285 after results of the Tuesday voting by 1,600 city Republicans were tabulated late Thursday night.

Former Gov. Linwood Holton claimed at least 93 firm delegates and supporters of former national GOP cochairman Richard D. Obenshain claimed about 65. The rest are presumed to be uncommitted or pledged to the fourth candidate in the Republican Senate race, state Sen. Nathan H. Miller of Rockingham County.

The Republican election in Alexandria was so complex that it defied conclusive analysis by the campaign staffs. "It's a mess," Holton supporter Jacqueline A. Jensen said. "The clear-out winner is going to be the candidate who manages to get the most delegates down to Richmond."

Alexandria has 57 votes out of 3,081 at the state convention in Richmond, June 2-3. However, party rules permit Republicans in every city and county to send five delegates for each vote, giving Alexandria a total of 285 delegates.

Republicans who voted Tuesday were confronted with a ballet listing 347 delegates candidates, almost all of them combined into two separate slates. One slate - the V slate - was considered to be for Holston and the other - the X slate - was considered to be for Warner and Obenshain. However, cross filing was permitted, and resulted in the listing of 40 candidates on both slates.

Adding to this confusion was the fact that the ballet also listed at-large slates and precinct candidates for the 120-member Republican city committee. In fact, the city committee race that pitted the party's moderate and conservative factions against each other, overshadowed the delegates election.

The moderates won a thumping victory, taking about 80 percent of the committee seats and electing Nancy McCabe city chairman. McCabe was campaign manager for State Del. Gary Myers, who upset former House of Delegates Majority Leader James M. Thomson in last fall's legislative election.

The Alexandria delegate election was the first to be held in a populous city or county. Warner, hoping for the psychological advantage of an early victory, mailed literature to voters in the last two Republican primaries and operated a bank of seven telephones for five days before the election.

The Holton campaign ran a single newspaper ad and sent a mailing to delegate candidates identified as Holton supporters. Both Holton and Warner visited polling places on election.

Obenshain's manager, William Dalton, said of his candidate's effort in Alexandria: "We saw it developing as a contest between two Northern Virginians and decided to committ our resources elsewhere. We think we came out very well."

Obenshain lives in Richmond and is expected to draw his greatest support from central and south central Virginia. In the first delegate selection caucus last Sunday, Dalton said, Obenshain won 9 of 11 convention vote from Nottoway County.

Despite the apparent adge in Alexandria delegates for Warner, Holton said he believes he should be considered winner of the popular vote because Obenshain and Warner supporters were combined on a single slate.

The Warer-Obenshain slate received about 58 percent of the vote to about 42 percent for the Holton slate.

"The last time I was in a three-way race, the fellow who got as much of the vote as I did Tuesday was declared governor of Virginia," Holton said. This was a reference to the 1965 state election when former governor Mills E. Godwin, then a Democrat, beat Holton with 47.9 percent of the vote.