Avco Corp., the conglomerate, today reported higher earnings for the second quarter ended May 31, although first-half earnings dropped below year-earlier results.

For the second quarter, the company had net income of $29.4 million ($1.26 a share), up from $27.7 million ($1.22 a share) in the year-ago period. Revenues rose 14 per cent to $161.9 million from $150.2 million.

For the first six months, the company earned $51.3 million ($2.21 a share) down from $59.0 million ($2.60 a share) in the first half last year. Six-month revenues totaled $29.10 million, up 11 per cent from $271.8 million a year earlier.

James R. Kerr, chairman and chief executive, and George L. Hogeman, president and chief operating officer, said the revenue gains were posted primarily by Avco Financial Services' Finance and Insurance Operations, Lycoming Stratford, Avco Community Developers, Paul Revere Life Insurance Co. and Embassy Pictures.

Lukens Steel Co. reported sharply higher second-quarter earnings for the three months ended June 11 of $1.64 a share against 79 cents a share in the same quarter last year.

In the second quarter, the company had net income of $4.21 million, compared with $2.03 million in the year-earlier period. Sales climbed to $65.49 million from $56.86 million.

For the first half of 1977, the company earned $4.14 million ($1.61 a share), down slightly from $4.16 million ($1.63 a share) in the first six months of 1976. Sales totaled $116.65 million, compared with $111.61 million.