City transit riders worried about potential service cuts and a 5% fare hike next year can rest a little easier after the chairman of the Metropolitan Transportation Authority yesterday abruptly announced that he opposed such moves in 2007.

The chairman, Peter Kalikow, issued a statement denouncing proposed reductions in service just hours after the president of the Transport Workers Union Local 100, Roger Toussaint, criticized the MTA for even considering the idea. Earlier yesterday, the transit authority had confirmed a proposed $20 million budget cut that would reduce bus and subway service during off-peak hours, creating longer waits.

At an afternoon press conference on the Upper West Side, Mr. Toussaint derided the MTA for contemplating service reductions at a time when ridership on the city’s subways and buses is at record levels.

In a statement hours later, Mr. Kalikow echoed that sentiment. “In the last decade alone, we have seen ridership on the subways and buses increase over 582 million,” he said. “Now is simply not the time to reduce services to our commuters.”

“We view fare increases as a last resort,” the chairman said, “and if revenues keep pace, I just don’t see a fare increase in 2007.”

The suggested cuts were part of the authority’s official budget proposal in July. They are a direct result of a looming MTA budget deficit that officials estimate will surpass $1 billion by 2009. The authority’s board is set to discuss the proposal at a meeting next week.

The MTA had initially planned to raise fares in January of next year, but increased revenue projections caused the authority to delay the proposed hike until September 2007 at the earliest. Mr. Kalikow’s statement could be an indication that any increase may be delayed even longer.

Both MTA officials and observers of transit issues appeared to be caught off-guard by Mr. Kalikow’s abrupt change of course.

“The chairman’s statement is truly unprecedented,” the coordinator for the riders advocacy group Straphangers Campaign, Neysa Pranger, said.

While board members can overrule Mr. Kalikow, the longtime chairman wields significant clout, making it unlikely that the proposed cuts will be approved.

Mr. Toussaint, who has frequently clashed with Mr. Kalikow and led transit workers on an illegal strike last December, applauded what the union called a “change of heart” by the chairman. “We are glad that it took Chairman Kalikow only a couple of hours to see the light this time,” Mr. Toussaint said in a statement.”We stand with the riders when we say that not another dollar should be cut from the service or safety concerns of passengers until the MTA trims the fat from its own bloated administrative staff — they need to cut the suits, not the service.”

Mr. Kalikow’s statement also comes as his stewardship of the MTA may be winding down. Governor Pataki, who will leave office at the end of the year, reappointed Mr. Kalikow to another six-year term, but the gubernatorial front-runner, Eliot Spitzer, has said he will try to oust the chairman in January. Mr. Kalikow has vowed to stay on, prompting a possible confrontation if Mr. Spitzer is elected.