Citing "significant conceptual deficiencies" in the varied definitions of key financial reporting elements used by American corporations, a board that sets standards for accountants yesterday proposed a uniform policy to cover business statements.

The Financial Accounting Standards Board, which issued the proposal and called for public comments by May 15, said it is a "major effort to gain consensus" on financial reporting.

The FASB's proposed document defines eight elements that measure performance of a business enterprise: assets, liabilities, owners' equity, comprehensive income, revenues, expenses, gains and losses.

Robert Sprouse, the FASB vice chairman, noted yesterday that definitions of these terms have been provided by dictionaries and textbooks and even in pronouncements of authoritative rule-making institutions.

But the definitions often differ on significant matters, and pronouncements by rule-making bodies have purported to rely on existing practices, he said.

"As a result, they . . . have failed to provide a basis for deciding whether an item is or is not an asset, liability, revenue or expense of a particular enterprise at a particular time. To be useful, a definition must set some limits," Sprouse asserted.

For example, Sprouse said that under the proposed FASB standards, deferred losses on an asset no longer held would not qualify as an asset. Another example would be that estimated possible casualty losses from a future flood or fire wouldn't qualify as a liability.

The proposed definition of assets is probable future economic benefits obtained or controlled by a particular enterprise as a result of past transactions of events affecting the enterprise.

Among the essential characteristics of an asset would be future economic benefit, the most obvious evidence of which is that it is an item commonly bought or sold; it has a market price. In addition, an asset could be any item that a creditor usually accepts in settlement of liabilities and anything commonly used to produce goods or services.

Sprouse said the proposed definitions wouldn't presage upheavals in accounting practices in the near future but could lead to some changes.