Despite growing interest in the firm bargaining process, little research focuses on the structure of bargaining within multi-establishment firms. We question whether running negotiations at the workplace level and/or firm level is a strategic choice for employers. We hypothesize that the level chosen depends on the geography of the firm. Employers face a trade-off: workplace bargaining is more efficient because it meets local conditions; yet higher level negotiations increase coordination costs for workers and weakens their bargaining power, which can benefit the employer. Using a French representative survey, we find a significant relation between the level of bargaining within a firm and the number, spatial distribution and heterogeneity of its establishments, suggesting that the structure of multi-establishment firms can inform the level at which collective bargaining takes place.@en