The House Ways and Means Committee completed action yesterday on a bill to increase Social Security taxes substantially over the next decade, after killing a move to raise the basic Social Security retirement age from 65 to 68.

The bill, designed to prevent the Social Security trust funds from going broke, would raise both the payroll tax rate and the maximum wage on which the tax is levied, for both employers and employees. Some increases were already scheduled, but the financing package put together by the committee's Democrats goes far beyond them and would boost both the rates and the maximum taxable wage much more.

The tax rate, currently 5.85 per cent each for employers and employees, would rise to 6.05 per cent in 1978 (as previously scheduled). 6.45 per cent in 1981. 6.75 per cent in 1985. 6.9 per cent in 1986 and 7.45 per cent in 1990.

The maximum taxable wage, now $16,500, would rise to $19,900 next year, $22,900 in 1979. $25,900 in 1980, and upward in further steps to $35,500 in 1986 and $39,600 in 1987.

Rep. Jim Guy Tucker (D-Ark.) and other sponsors said most of the big increases in taxes paid would fall on the higher-paid workers because of rapid increases in the wage base, but there will be increases also for lower-paid workers because of changes in the tax rate.

At present, according to an illustration given by Tucker, a worker making $10,000 a year pays $585 a year in Social Security taxes and his employer the same. But by 1986 under the bill this would rise to $690. A worker making $16,500 a year (the maximum taxalbe wage in 1977) pays taxes of $965, which would rise to $1,138 in 1986.

However, a worker making $37,500 now, who pays only $965 in taxes this year because he's only taxes on the first $16,500, would be paying $2,588 in 1986 because the taxable base by then would have risen to $37,500. This means almost a tripling of payments for this worker and his employer over 1977 figures.

In addition to the tax increases, the bill also contains long-range changes in the benefit formula, and would bring federal, state and local government employees under Social Security on Jan. 1, 1982, would raise the amount a retired person can earn without loss of benefits from $3,000 now to $4,000 next year and $4,500 in 1979, and would make a number of changes benefiting widows and ending sex-distinctions in the benefit structure.

In last-minute action yesterday, the committee added a provision authorizing agreements between the United States and other countries for a system of combining Social Security wage credits and ending some double tax payments for a U.S. resident who works in both the United States and other countries.

The most dramatic vote, however, was the 24-to-11 rejection of a proposal to raise the basic retirement age under Social Scurity to 68 by the year 2001. At present it is 65, and a person who opts to retire at 62 has monthly benefits reduced by 20 per cent.

Republicans, as part of an alternative package of their own, had proposed using 68 as the basic year.Anyone retiring at 62 would have a 40 per cent reduction of monthly benefits, and anyone retiring at 65 would have a 20 per cent reduction.

They protested when Otis G. Pike (D-N.Y.) proposed a separate vote on the age 68 proposal. They said it should be considered only as part of their long-range package. But the vote was taken anyhow, and virtually all Democrats and a cluster of Republicans voted no.

Chairman Al Ullman (D-Ore.), endorsing the final bill, indicated that he expected attempts on the floor to remove coverage of federal employees (their unions fear it will mean substantial future reduction of Civil Service retirement benefits), to install the GOP package or to raise the earnings limit for retirees higher than $4,500.

Rep. James A. Burke (D-Mass.) said getting a bill through this year is so important to save the Social Security funds that he may ask the Democratic Caucus for assurances that there will be no adjournment until a bill is passed. The committee actuary said the new financing in the bill would carry the old-age and disability trust funds to about the year 2010 before they begin running a deficit, and the health-insurance fund to about 1990. Otherwise all would be in serious trouble in the next few years.

In addition to the financing changes, rise in the earnings limit and coverage for government employees the bill would:

Install a new formula for long-range benefits, starting in 1979, that would return the average worker an initial monthly benefit when he or she retires equal to about 43 per cent of his or her average monthly earnings in the year before retirement. After that, his payments would rise with the cost of living. The present ratio is 45 per cent. This change, which would save billions of dollars a year beginning in a few years, would wipe out an unintended effect of a 1972 formula that was pushing future benefits up much faster than foreseen at the time with the danger of total permanent bankruptcy.

At present the minimum benefit to a worker retiring on his or her own earnings record is $114 a month, and the maximum for a worker of 65 who is retiring right now is about $437 a month Extra, is paid for dependents.

Under the committee bill, as a result of wage base increases and formula changes, a worker retiring in 1986 at age 65 after having worked at the top taxable salary through his or her life would receive $750. Social Security officials estimated last night.

Permit the trust funds to borrow from the Treasury when their reserves are less than 25 per cent of a year's benefits, but would require an automatic payroll tax rise to recoup two years after the loan is taken.

Freeze the present regular minimum benefit at $120, but would provide that a "special minumum" for long-term, low-paid workers be increased from $9 a month to $11.50 for each year a person works in covered employment in excess of 10 years and up to 30.

Increase the bonus payment for persons delaying retirement past 65 from 1 per cent extra for each year of delay to 3 per cent.

Eliminate certain see distinctions so that male dependents and survivors could receive benefits on the same basis as women; would permit aged widows or widowers to remarry without loss of benefits, and would permit a divorced spouse to receive dependent or survivor benefit if the original marriage were five years or more, instead of the 20 years now required. The minimum benefit and various spouse benefits were initially proposed by republicans.

The Social Security trust funds are facing heavy deficits because high unemployment in recent years has robbed them of some payroll tax income they otherwise might have received, and because the propostion of aged persons in the population is rising, meaning there are relatively fewer active worker to support the benefits.