Negotiations between representatives of 14 San Francisco hotels and the union that represents 4,000 locked-out union workers may not resume until week's end, both sides said Monday.

Picket lines remain at the 14 hotels, and the plans of some guests are in flux. There have been no cancellations of major conventions, but some meetings at the hotels have been scaled back or moved, said Mark Theis, vice president of conventions at the San Francisco Convention & Visitors Bureau.

The employers are preparing responses to the union's questions about a proposal presented Friday on health care cost-sharing, said Barbara French, spokeswoman for the hotels.

For 20 years, members of the union, Unite Here Local 2, have paid $10 per month toward their health insurance premiums.

Under a revised proposal they would have two options: One would require an individual to pay $46 per month in the first year, with a $10 co-payment, and $112 per month in years three, four and five of the contract. Workers with dependent coverage would pay more.

In a second option, individuals would pay $36 per month, with a $20 co- payment, in the first year and $102 monthly in years three, four and five. Again, the monthly contributions for employees with dependents would be higher.

The union wants the current health care arrangement to continue.

The 14 hotels joined together to negotiate labor contracts. The union struck four of them on Sept. 29, for what was said to be for two weeks. In response, the employers locked out workers at the other 10 hotels on Oct. 1. On Wednesday, all 14 hotels locked out the workers who had gone on strike.

While a number of planned gatherings at the hotels have been affected by the dispute, others are proceeding. For example, a major fund-raiser for the Northern California Arthritis Foundation, a fashion show and luncheon today at the Westin St. Francis Hotel, will go on as scheduled despite the picket line. Some 500 people are expected.

"The strike is an unfortunate situation, but we're looking at raising about $100,000, maybe more, with the silent and live auctions, and we're moving ahead,'' said Peggy O'Neill, vice president of development for the foundation.

Meanwhile, locked-out union workers will be picking up donated food at a giveaway at the Bill Graham Civic Auditorium, from 8 a.m. until 6 p.m. today.

Chronicle staff writer Sylvia Rubin contributed to this report.