Metro General Manager Richard S. Page told the Arlington County Board last night he hopes local governments will strongly back his efforts to control the rate of automatic pay increases for Metro's drivers, train operators, station attendants and mechanics.

It was Page's strongest public comment to date on the increasingly controversial cost-of-living raises the 4,800 unionized transit employes receive. Metro is negotiating with Local 689 of the Amalgamated Transit Union to replace a contract that expires Arpil 30.

"I'm not antiunion," Page said, "but this is the only public employe union I know of that has point-for-point protection against inflation every quarter. iWe have to break that some time."

He recommended that the Arlington Board and other local jurisdictions support his suggestion of a 6 percent cap on pay increases for the transit union. Last week Metro's transit union employes received a 26-cent-an-hour increase, which represented an 18 percent jump in the cost of living in the last two months of 1979.

That increased the hourly wage of an experienced bus driver or train operator to $9.86 or $20,508 per year.

Page said that with a 6 percent cap he could reduce local subsidy to Metro in fiscal 1981 by $2.2 million. Along with other cuts and a projected increase in federal aid, Page said, the Metro board's proposed 1981 local subsidy level could be cut $8.9 million.,

The Arlington County Board has told Page that it will pay no more than $9 million in Metro subsidy for 1981. With the projected cost of living cap and other reductions, Page said, the Arlington share of Metro's projected $152 million deficit would be $10.2 million, a reduction of $697,000 from earlier projections.

There was no immediate reaction from the board last night other than encouragement for continued effort at budget cutting.

Arlington is one of many local governments saying that Metro's costs must be trimmed. Page's new proposals would decrease the D.C. subsidy by $4.4 million, Montgomery County's by $1.1 million, Prince George's County's by $1.3 million, Fairfax County's by $1 million, and Alexandria's by $429,000.

Page said he will oppose attempts to cut bus and subway maintenance, as some County Board members have suggested. "I'm telling you we are behind in our maintenance," Page said.