Marriott Corp. began a public offering for limited partnerships yesterday in a new venture formed to finance and develop hotels for the Bethesda-based food and lodging company.

Marriott announced that the offering had begun after the Securities and Exchange Commission had declared its registration statement effective. The offering--1,800 units at $10,000 each--totals $18 million.

Marriott said it will act as sole general partner in the partnership, which will develop, own and operate 11 hotels as part of the Marriott chain.

A group of commercial banks has agreed to lend the partnership up to $456.25 million to finance development and construction of the hotels. Financing will be provided by Bankers Trust Co. and Manufacturers Hanover Trust Co. of New York, First National Bank of Chicago and Security Pacific National Bank of Los Angeles.

The partnership will pay the banks interest ranging from 2 to 3 3/4 percentage points above the 90-day certificate of deposit rate reported by the New York Federal Reserve Bank.

Warburg Paribas Becker-A.G. Becker is dealer-manager for the offering.

The new enterprise, called Potomac Limited Partnership, represents an unusual financing plan for Marriott which, until now, has borrowed from insurance companies and other institutional investors to finance its hotels.

Through the limited partnerships, Marriott is selling tax shelters to the public. Investors who participate in the venture could possibly earn five times their investment in tax deductions, according to a preliminary offering statement made public earlier this year.

The offering statement that Marriott filed with the SEC emphasized that investing in the partnership is only for investors in top income brackets. The tax deductions will be of little benefit to persons who pay less than 42 percent of their income in taxes and are best for those paying the maximum rate of 50 percent, according to the statement.