Undated (AP) _ Greyhound's 6,300 drivers went on strike early today at the country's only nationwide bus company, stopping their buses outside terminals and stranding thousands of travelers.

The walkout over wages began after contract talks in Scottsdale, Ariz., between Greyhound Lines Inc. and the Amalgamated Council of Greyhound Local Unions failed to reach an agreement by the 12:01 a.m. MST strike deadline.

No new negotiations were scheduled.

Stranded passengers complained that they were unaware that a strike was looming and criticized Greyhound for selling them tickets when it was likely they wouldn't be able to complete their trips.

''They haven't even apologized,'' said Lisa Olkon, who was stuck in Atlanta while trying to get home to St. Paul, Minn., from Florida. ''I called about an hour before I went to get on the bus'' and was told nothing.

About 200 passengers had been stranded at the Atlanta terminal early today, but by late morning only three dozen or so remained. The others apparently got out on the few buses that did depart or on a southbound Amtrak train that left at midmorning, or found lodging to wait out the strike.

''We went on strike because the company has refused to bargain in good faith, and we have struck because the company insisted on imposing'' its original offer, said union spokesman Jeffrey Nelson.

Besides the 6,300 drivers, the strikers include 3,075 of the company's office and maintenance workers whose three-year contract expired at midnight.

Dallas-based Greyhound carried 22 million passengers last year, an average of about 60,000 a day. The union told its drivers to continue only as far as their next destination as the strike deadline passed. The company said it didn't know how many passengers were stranded, but estimated the number in the thousands.

Greyhound said it would operate a limited schedule today using replacements trained during the past few weeks.

''We are starting with our main line schedule first, and continue to add routes as drivers become available,'' spokeswoman Liz Hale said from the company headquarters.

She said at least 16 of the 60 bus schedules that the company normally runs in Dallas were operating as of 6 a.m.

Hale also said some drivers had crossed picket lines, but didn't know how many. Later, she said she had received ''spotty reports'' of harassment on picket lines, but ''nothing involving passengers.'' She said she could not confirm any of the incidents.

Amtrak told ticket agents to honor Greyhound tickets when buses are unavailable, said railroad spokeswoman Sue Martin in Washington, D.C.

Greyhound serves about 9,500 destinations, including about 9,000 where it is the only intercity transportation.

It offers a $68 one-way ticket anywhere in the country and generally caters to people seeking the cheapest form of mass transit.

Only nine of the normally scheduled 40 Greyhound buses left the Port Authority terminal in New York City between 6 p.m. and midnight, so that all passengers would reach their final destinations, said Greyhound spokesman Bill Kula.

In Dallas, more than 40 pickets encircled the downtown bus terminal and blocked two incoming Greyhound buses, cheering when the drivers abandoned their vehicles.

A handful of pickets blocked a departing bus for about 20 minutes in Minneapolis.

The bus, marked ''charter,'' pulled out of the terminal onto a side street just before 8 a.m. when one picket, Mike Vervanac, pulled open the door and told the driver, ''We can't guarantee your safety down the road.''

Another picket, Joyce Wegener, called the driver a scab. She said later, ''The man's got my job.''

A security guard said police would be called and told the driver to continue. The bus halted again when pickets walked in front of it and didn't step aside until they saw police arriving. No arrests were made.

Rob Wilkins, 22, of London, said the strike had disrupted his plans to tour America by bus. He was trying to get from Minneapolis to Memphis, Tenn.

''I'm not going to see Elvis,'' he lamented. ''I come to bloody America and they're on strike.''

Several buses also were delayed in Cleveland, where pickets jeered and pounded their fists on departing and arriving vehicles. Police blocked pickets from approaching two buses that left the Philadelphia station without passengers. Company officials would not say where the buses were going.

In Pittsburgh, where violence broke out during a bus strike seven years ago, six workers picketed peacefully while stranded passengers snoozed.

Sharon Kois, a senior at West Virginia University in Morgantown, W.Va., was trying to get to Bozeman, Mont., for a job interview Saturday.

She said a ticket agent asked her, ''Don't you read the papers?'' when she arrived to catch her bus. She then reserved seats on an Amtrak train bound for Montana.

The company said it was unsure if the picket lines would be honored by other unions, including drivers at urban mass transit systems the company operates in various cities.

Greyhound drivers, who according to the company earned an average of $24,743 last year, took a 22 percent pay cut three years ago in negotiations prior to a leveraged buyout of the company.

The company is offering a first-year raise of 6.9 percent, but the union says this is misleading. The company says the union is demanding a 33 percent increase in the first year; the union says that is a distortion.

Greyhound Chairman Fred G. Currey led an investment group that paid Phoenix-based Greyhound Corp. $270 million to buy out the company in 1987. The group later bought Trailways Lines Inc. of Dallas for $80 million and merged the two companies.

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