Lotus Development Corp., the enormously successful microcomputer software company, announced plans today to buy the major assets of Software Arts Inc., the financially troubled developer of VisiCalc, once the best-selling business productivity program.

Terms of the agreement were not disclosed, except that it was a cash transaction.

"We're not getting rich on this deal," noted Daniel S. Bricklin, Software Arts chairman, who with company president Robert M. Frankston developed VisiCalc, the original spreadsheet program that put personal computers in corporate offices.

The proposed acquisition joins Bricklin and Frankston with Mitchell D. Kapor, the former VisiCalc marketing manager who went on to form Lotus Development, where the success of 1-2-3, a second-generation business program, generated nearly $157 million in revenue last year, nearly triple the previous year's revenue of $53 million.

Software Arts of Wellesley, Mass., by comparison, has fallen on tough times, as revenue dipped to an estimated $3 million last year, down from $12 million the previous year.

The agreement is the latest in what is expected to be a series of software consolidations this year. Large, prosperous firms such as Lotus, Cullinet Software of Westwood and Ashton-Tate Corp. of Culver City, Calif. are besieged by small, underfinanced software companies that need help to survive.

The announcement today is seen in software circles much like a son taking care of his father: Lotus, the youthful, ambitious and wealthy offspring making sure the elder Software Arts doesn't fade away.

"It is ironic that our situations have changed," said Kapor, who has known Bricklin and Frankston since the late 1970s when, as Apple Computer users, they helped promote the Boston Computer Society. "We've come full circle."

"Lotus appreciates what we have done," added Bricklin. "Together we have made Boston the hub of the software universe when it comes to innovation."