By Bill Koenig and Katie Merx

May 11 (Bloomberg) -- General Motors Corp. is not planning to modify terms of a bond exchange, Chief Executive Officer Fritz Henderson said on a conference call.

GM’s plan envisions that the U.S. would control at least 50 percent of 60 billion shares in a restructured company, and a union-run health-care fund would get as much as 39 percent. Unsecured bondholders would get 10 percent and existing shareholders would get 1 percent, GM said.

Bondholders would receive 225 shares in the new automaker for each $1,000 in principal. When the exchange is complete, GM would do a 1-for-100 reverse split of the stock.

Bondholders countered that proposal with a plan calling for GM to give them 58 percent of the equity in the reorganized company. Henderson said last week that the U.S. Treasury has indicated it “would not be supportive of shareholding in excess of 10 percent” for the bondholders.

Without support from 90 percent of the bondholders by May 26, GM plans to file for bankruptcy by June 1. GM hopes to avoid a bankruptcy, Chief Financial Officer Ray Young said last week, adding that if one is needed GM wants to go in and out of court quickly.

GM fell 18 cents, or 11 percent, to $1.43 at 9:48 a.m. in New York Stock Exchange composite trading. The shares have declined 55 percent this year.

To contact the reporter on this story: Katie Merx in Southfield, Michigan at kmerx@bloomberg.net