Federally chartered savings and loan associations closed out their best savings year ever with a December net savings inflow that set a record for the month. The S&Ls also had record mortgage-lending volume last year.

New deposits at S&Ls exceeded withdrawals by $2.29 billion in December, down slightly from November's net savings inflow of $2.38 billion, the Federal Home Loan Bank Board said. But December's savings gain was more than double the December 1975 net inflow of $968 million and also was nearly twice the previous December record of $1.2 billion set in 1971.

December inflow boosted the net savings gain for the year to a record $34.38 billion, up 17 per cent from the previous high of $29.30 billion reached in 1975.

Mortgage lending by S&Ls totaled a record $7.11 billion in December, up from $6.39 billion in November and 38 per cent above the $5.14 billion a year earlier, the board said. The increased lending volume was counter to the usual pattern of a drop-off between November and December. Mortgage lending by S&Ls for the year totaled $77.08 billion, 43 per cent above the previous high of $53.80 billion in 1975.