The Metro Board proposed major fare increases yesterday for all subway riders and suburban bus passengers beginning July 1 as a means of party offsetting the increased subsidy projected in Metro's record budget for the next fiscal year.

The board budget anticipates a 7 percent across-the-board increase in subway fares, which for practical purposes would result in a five-cent increase on a 50-cent ride. Suburban bus riders would pay a 10 percent increase, which means a $1 bus trip would go to $1.10.

Such fare increases would raise $6.2 million toward financing a record Metro operating budget of $276.8 million. Of that total, $126.4 million would have to be provided by local governments, a 35 percent increase over the current budgeted subsidy of $93.4 million.Metro. The Arlington County Board has already said its share -- projected at $10.8 million -- is nearly $2 million more than it will pay, and that it will not accept a cut in transit service.

Other local governments are also complaining about spiraling Metro costs as they seek authority from the Maryland and Virginia legislatures to take the cost of operating Metro off the Politically sensitive property tax.

Specific new fare schedules have yet to be decided by the board. Various proposals will be presented at public hearing in months to come and the new fares will take effect July 1, the beginning of Metro's 1981 fiscal year. n

The boards's budget anticipates no change in District of Columbia bus fares, which are 50 cents for rush-hour trips (6 a.m. to 9:30 a.m. and 3 p.m. to 6:30 p.m. weekdays) and 40 cents the rest of the time.

District of Columbia representatives have resisted fare increases in recent years, saying they prefer to increase their subsidy to Metro. However, D.C. officials say, that policy may have to be revised next year if not this year because of growing revenue problems for the District.

The Metro board's budget comes after three months of hearings on a proposal last September from General Manager Richard S. Page. Now the budget will go to eight local governments for comment before it can be finally be adopted.

The board's budget committee, despite carefful scrutiny of Page's proposal, was unable to make any cuts. Because the committee directed that higher costs be anticipated in the budget for both diesal fuel and inflation-driven salaries, the budget is fractionally higher than Page's proposal. Only the fare increase reduces the projected impact of the subsidy. p

The board went along with Page's insistance that general maintenance of both the bus and subway systems has to be improved and 100 new employes have been approved. Other factors driving the budget higher are:

The scheduled opening in November of the Blue Line subway extension from Stadium-Armory out East Capital Street and Central Avenue to Addison Road in Prince George's County.

A 33 percent increase in claims, from $10.9 million to $14.6 million, reflecting major increases in workers compensation for Metro employes and casualty and liability payments to Metro users and others.

An anticipated inflation rate of 10 percent, which reflects directly in the salaries of Metro's unionized bus driviers, train operators, mechanics, station atendants and others. The transit union is guaranteed, by contract a quarterly cost-of-living increase that reflects the D.C. Consumer Price Index point for point.

Enormous increases in diesel fuel costs for the bus system. Fuel and lubricants cost $7.7 million in 1979; for 1981 they are projected at $15.9, an increase of 106 percent.

The budget committee rejected two of page's proposals. One was for eight more hours of subway service on Sundays, when the trains run only from 10 a.m. to 6 p.m. That proposal would have cost Metro about $1 million. Page also proposed cutting about 66 bus trips daily to make the system "more efficient" and save $4 million. That service cut was rejected.

The board forwarded the budget yesterday to local governments along with an instruction to Page to meet with Arlington County officials -- and determine what reductions can be made. The county has said it will pay no more than $9 million. The new budget projection shows Arlington paying $10.8 million.

If there is no resolution of the impasse between Metro and Arlington, "I'm not sure I'll vote for a budget that is not funded," said Metro board member Francis B. Francois of Prince George's County.

Dorothy Grotos, Arlington's Metro board member, said, "There are ways Metro can save money without cutting service."